Abdominal aortic aneurysm facts An aneurysm is an abnormal area of localized widening of a blood vessel. The aorta bulges at the site of an aneurysm like a weak spot on a worn tire. Aortic aneurysms are typically ...

Abdominal aortic aneurysm facts An aneurysm is an abnormal area of localized widening of a blood vessel. The aorta bulges at the site of an aneurysm like a weak spot on a worn tire. Aortic aneurysms are typically ...

Fetal retinoid syndrome is a characteristic pattern of mental and physical birth defects that results from maternal use of retinoids, the synthetic derivatives of vitamin A, during pregnancy. The most well known retinoid is isotretinoin (Accutane)...

Achalasia is a rare disease of the muscle of the esophagus (swallowing tube). The term achalasia means "failure to relax" and refers to the inability of the lower esophageal sphincter (a ring of muscle situated between the lower esophagus and the ...

Gaucher disease is a rare, inherited metabolic disorder in which deficiency of the enzyme glucocerebrosidase results in the accumulation of harmful quantities of certain fats (lipids), specifically the glycolipid glucocerebroside, throughout the b...

A rare genetic condition where the body can't process proteins adequately. More specifically, there are insufficient levels of the enzyme needed to break down an amino acid called leucine. This results in a build up of isovaleric acid which can harm ...

Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. It often causes whiteheads, blackheads or pimples, and usually appears on the face, forehead, chest, upper back and shoulders. Acne is most ...

Acne (acne vulgaris, common acne) is a disease of the hair follicles of the face, chest, and back that affects almost all teenagers during puberty -- the only exception being members of a few primitive Neolithic tribes living in isolatio...

Osteopetrosis may be inherited as either a dominant or recessive trait and is marked by increased bone density, brittle bones, and, in some cases, skeletal abnormalities. Although symptoms may not initially be apparent in people with mild forms of...

Tangier Disease is an inherited blood disorder involving decreased concentrations of fat compounds in the blood called high-density lipoproteins (sometimes called "good cholesterol"). Large amounts of these compounds may accumulate in certain orga...

What is alpha thalassemia? Alpha thalassemia is a blood disorder that reduces the production of normal hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen to cells throughout the body. What are the types of...

Amyotrophic lateral sclerosis facts Amyotrophic lateral sclerosis is a rapidly progressive, invariably fatal neurological disease that attacks the nerve cells responsible for controlling voluntary muscles. Amyotrophic late...

What is sickle cell anemia? Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by an inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (...

What is sickle cell anemia? Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by an inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (...

Ankylosing spondylitis facts Ankylosing spondylitis belongs to a group of arthritis conditions that tend to cause chronic inflammation of the spine (spondyloarthropathies). Ankylosing spondylitis affects males two to three...

Anorexia nervosa facts Anorexia nervosa is a a psychiatric condition, which is part of a group of eating disorders. The cause of anorexia has not been definitively established, but self-esteem and body-image issues, societ...

Antley-Bixler Syndrome is a rare genetic disorder that is primarily characterized by distinctive malformations of the head and facial (craniofacial) area and additional skeletal abnormalities. For example, the disorder is typically associated with...

Arachnoiditis is a pain disorder caused by the inflammation of the arachnoid, one of the membranes that surround and protect the nerves of the spinal cord. It is characterized by severe stinging, "burning pain", and neurological problems....

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm probl...

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm problems (heart arrhythmias) occur when the electrical signals that coordinate the heart's beats don't work properly. The faulty signalling causes the heart to beat too fas...

Polymyalgia rheumatica is a rare inflammatory disease characterized by muscle pain (myalgia), stiffness, and additional generalized systemic symptoms such as fatigue, low-grade fever, and/or a general feeling of ill health (malaise). Polymyalgia r...

Auditory Processing Disorder (APD) is a complex problem. The term is used by many people, in very different ways. There is research underway to help understand this disorder. There also is research to investigate therapies that will help individua...

Jervell and Lange-Nielsen syndrome (JLNS) is a rare inherited disorder characterized by deafness present at birth (congenital) occurring in association with abnormalities affecting the electrical system of the heart. The severity of cardiac sympto...

Giant axonal neuropathy is a rare neuropathy that severely affects the peripheral as well as the central nervous system. The first symptoms appear in early childhood. This disorder is characterized by abnormalities in the peripheral and central ne...

Batten Turner Type Congenital Myopathy is an extremely rare, inherited muscle disease (myopathy) and is characterized by the lack of muscle tone or floppiness at birth (congenital hypotonia). The symptoms of Batten Turner Type Congenital Myopathy ...

Beckwith-Wiedemann syndrome (BWS) is a rare genetic overgrowth disorder. It is characterized by a wide spectrum of symptoms and physical findings that vary in range and severity from case to case. However, in many individuals, associated features ...

Bile duct cancer, also called cholangiocarcinoma, is when unusual cells grow out of control inside your bile ducts. Those are thin tubes about 4 to 5 inches long that move a fluid called bile from your liver to your gallbladder and small intestine...

Bile duct cancer, also called cholangiocarcinoma, is when unusual cells grow out of control inside your bile ducts. Those are thin tubes about 4 to 5 inches long that move a fluid called bile from your liver to your gallbladder and small intestine...

Hairy tongue is an uncommon, benign condition that is also known as black hairy tongue or lingua nigra. It is characterized by abnormal elongation and blackish or dark brownish discoloration or "staining" of the thread-like elevations (filiform pa...

Boil  A boil is a painful, pus-filled bump under your skin — the result of a bacterial infection of one or more hair follicles. Carbuncle  A carbuncle is a cluster of boils — painful, pus-filled bumps ...

The botulism neurotoxin is one of the most potent, lethal substances known. Botulism is a disease caused by this neurotoxin (specifically A, B, E, or F type neurotoxin). The neurotoxin is produced by bacteria called Clostr...

Fukuyama type congenital muscular dystrophy (FCMD) is one of several forms of a rare type of muscular dystrophy known as congenital muscular dystrophy. It is inherited as an autosomal recessive trait. Symptoms of this disorder are apparent at birt...

Branchio-oculo-facial syndrome (BOFS) is a very rare genetic disorder that is apparent at birth (congenital). As of 2004, only about 50 cases of BOFS had been reported in the medical literature. The symptoms of most BOFS patients include the proli...

Acrodermatitis enteropathica (AE) is a disorder of zinc metabolism that occurs in one of two forms: an inborn (congenital) form and an acquired form. The inborn form of AE is a rare genetic disorder characterized by intestinal abnormalities that l...

Simpson dysmorphia syndrome types 1 and 2 are two forms of a rare, X-linked recessive, inherited disorder characterized by unusually large fetuses (prenatal overgrowth) and unusually large babies (postnatal overgrowth). In addition, affected indiv...

Campomelic dysplasia is a severe disorder that affects the development of the skeleton and reproductive system. This condition is often life-threatening in the newborn period. The term "campomelic" comes from the Greek words for "bent limb." Affec...

Campomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; oth...

Canker sores, also known as aphthous ulcers, are small, painful sores that develop on the inside of the mouth, on the gums, or on the tongue. They are usually round or oval in shape and have a white or yellow center with a red border. Canker sores...

Pentalogy of Cantrell is a rare disorder that is present at birth (congenital). Pentalogy of Cantrell is characterized by a combination of birth defects. These birth defects can potentially involve the breastbone (sternum), the muscle that separat...

Chanarin Dorfman syndrome is a rare hereditary disorder of fat (lipid) metabolism. It is characterized by scaly skin (ichthyosis), degeneration of the muscles (myopathy), and abnormal white blood cells with small spaces (vacuoles) filled with fat ...

Giant axonal neuropathy is a rare neuropathy that severely affects the peripheral as well as the central nervous system. The first symptoms appear in early childhood. This disorder is characterized by abnormalities in the peripheral and central ne...

Chlamydia is a common sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It can be transmitted through unprotected sexual contact with an infected person. Chlamydia can infect both men and women and can cause sympt...

Chlamydia is the most commonly reported sexually transmitted disease (STD) in the U.S. It is an infection with the bacteria known as Chlamydia trachomatis. Chlamydia is very similar to gonorrhea in its symptoms and pattern of transmission. It is i...

Mixed connective tissue disease facts Connective tissues are the framework of the cells of the body. Mixed connective tissue disease is an "overlap" combination of connective tissue diseases. Diagnosis of mixed c...

Carnitine palmitoyltransferase 1A deficiency (CPT1A) is characterized by a sudden onset of liver failure and damage to the nervous system resulting from liver failure (hepatic encephalopathy), usually associated with fasting or illness. CPT1A defi...

Cradle cap causes crusty or oily scaly patches on a baby's scalp. The condition isn't painful or itchy. But it can cause thick white or yellow scales that aren't easy to remove. Cradle cap usually clears up on its own in a few months. Home...

Chromosome 22q11.2 deletion syndrome is associated with a range of problems including: congenital heart disease, palate abnormalities, immune system dysfunction including autoimmune disease, low calcium (hypocalcemia) and other endocrine abnormali...

Craniofrontonasal dysplasia is a very rare inherited disorder characterized by abnormalities of the head and face (craniofacial area), hands and feet, and certain skeletal bones. Major symptoms of this disorder may include widely spaced eyes (ocul...

Crouzon syndrome is a rare genetic disorder that may be evident at birth (congenital) or during infancy. The disorder is characterized by distinctive malformations of the skull and facial (craniofacial) region. Such abnormalities may vary greatly ...

Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, invariably fatal brain disorder. It affects about one person in every one million people per year worldwide; in the United States there are about 200 cases per year. CJD usually appears in l...

Cystinuria facts Cystinuria is a relatively common inherited disorder. The disorder is due to a defect in the transport of amino acids including one called cystine. Cystinuria features too much cystine in the uri...

Cyst facts Cysts are closed sac-like or capsule structures that may be filled with semisolid material, gaseous material, or liquid. There are several causes of cysts, including genetic, infectious, and other causes that resu...

Autosomal dominant interstitial kidney disease describes a group of diseases affecting solely the proper function of the kidney and having the following characteristics: They are inherited in an autosomal dominant manner; kidney disease develops, ...

General DiscussionCytochrome C Oxidase deficiency is a very rare inherited metabolic disorder characterized by deficiency of the enzyme cytochrome C oxidase (COX), or Complex IV, an essential enzyme that is active in the subcellular struc...

Locked-in syndrome is a rare neurological disorder in which there is complete paralysis of all voluntary muscles except for the ones that control the movements of the eyes. Individuals with locked-in syndrome are conscious and awake, but have no a...

Dehydration facts The body needs water to function. Dehydration occurs when water intake is less than water loss. Symptoms range from mild to life-threatening. The young and the elderly are especially s...

Dental fluorosis is a condition that affects the teeth due to overexposure to fluoride during the early years of life. It can cause white or brown spots, streaks, or pits on the teeth, and in severe cases, it can lead to enamel erosion and discolo...

Dental plaque is a sticky, colorless film of bacteria that forms on the teeth and along the gumline. It is constantly forming on the teeth and can lead to tooth decay and gum disease if not removed regularly through proper oral hygiene practices s...

Neuropathy is damage to nerves, and diabetic neuropathy is damage to nerves that occurs as a result of diabetes. Diabetes is thought to damage nerves as a result of prolonged elevated levels of blood glucose. Diabetic neuropathy can affect differe...

Hereditary multiple osteochondromas (HMO) is a rare genetic disorder characterized by multiple benign (noncancerous) bone tumors that are covered by cartilage (osteochondromas), often on the growing end (metaphysis) of the long bones of the legs, ...

Dyggve-Melchior-Clausen (DMC) syndrome is a rare, progressive genetic disorder characterized by abnormal skeletal development, microcephaly and intellectual disability. The condition was first reported by Dyggve, Melchior and Clausen in 1962 in th...

Dyggve-Melchior-Clausen (DMC) syndrome is a rare, progressive genetic disorder characterized by abnormal skeletal development, microcephaly and intellectual disability. The condition was first reported by Dyggve, Melchior and Clausen in 1962 in th...

Chanarin Dorfman syndrome is a rare hereditary disorder of fat (lipid) metabolism. It is characterized by scaly skin (ichthyosis), degeneration of the muscles (myopathy), and abnormal white blood cells with small spaces (vacuoles) filled with fat ...

Dry mouth, also known as xerostomia, is a condition in which the salivary glands do not produce enough saliva to keep the mouth moist. This can lead to a variety of symptoms, including a dry, sticky feeling in the mouth, difficulty swallowing or s...

Dermatitis herpetiformis, also known as Duhring disease, is a rare, chronic, skin disorder characterized by the presence of groups of severely itchy (pruritic) blisters and raised skin lesions (papules). These are more common on the knees, elbows,...

Trisomy 5p is a rare chromosomal disorder in which all or a portion of the short arm (p) of chromosome 5 (5p) appears three times (trisomy) rather than twice in cells of the body. Often the duplicated portion of 5p (trisomy) is due to a complex re...

Keratosis follicularis, also known as Darier disease, is a rare, genetic skin disorder. Affected individuals develop skin lesions that consist of thickened, rough bumps (papules) or plaques that may also be greasy or have a brown or yellow crust. ...

Dysthymia, now referred to as persistent depressive disorder, is a form of depression that lasts more than two years at a time in adults and more than one year at a time in children and adolescents. Dysthymia can afflict 3%-6% of th...

Trisomy 18 syndrome is a rare chromosomal disorder in which all or a critical region of chromosome 18 appears three times (trisomy) rather than twice in cells of the body. In some cases, the chromosomal abnormality may be present in only a percent...

Emery-Dreifuss muscular dystrophy (EDMD) is a rare, often slowly progressive genetic disorder affecting the muscles of the arms, legs, face, neck, spine and heart. The disorder consists of the clinical triad of weakness and degeneration (atrophy) ...

Encephaloceles are rare birth defects associated with skull defects characterized by partial lacking of bone fusion leaving a gap through which a portion of the brain sticks out (protrudes). In some cases, cerebrospinal fluid or the membranes that...

Ollier disease is a rare skeletal disorder characterized by abnormal bone development (skeletal dysplasia). While this disorder may be present at birth (congenital); it may not become apparent until early childhood when symptoms, such as deformiti...

Atrioventricular septal defect (ASVD) is a general term for a group of rare heart defects that are present at birth (congenital). Infants with ASVDs have improperly developed atrial and ventricular septa and adjoining valves. The norma...

Achalasia is a rare disorder of the esophagus, the tube that carries food from the throat to the stomach. It is characterized by enlargement of the esophagus, impaired ability to push food down toward the stomach (peristalsis), and failure of the ...

What is the esophagus? The esophagus is a muscular tube in the chest. It's about 10 inches (25 centimeters) long. This organ is part of the digestive tract. Food moves from the mouth through the esophagus to the stomach. Th...

Oculo-auriculo-vertebral spectrum (OAVS) refers to three rare disorders that many clinicians believe to be intimately related to one another and which represent the range of severity of the same disorder. These disorders are apparent at birth (con...

Facioscapulohumeral muscular dystrophy (FSHD), also known as Landouzy-Dejerine muscular dystrophy, is a neuromuscular disorder. Symptom onset usually occurs in adolescence or early adulthood; however, less commonly, symptoms may become apparent as...

Gilbert syndrome is a mild genetic liver disorder in which the body cannot properly process bilirubin, a yellowish waste product that is formed when old or worn out red blood cells are broken down (hemolysis). Individuals with Gilbert syndrome hav...

You have flatfeet when the arches on the inside of your feet are flattened, allowing the entire soles of your feet to touch the floor when you stand up. A common and usually painless condition, flatfeet can occur when the arches don't deve...

Fraser syndrome is a rare genetic disorder characterized by partial webbing of the fingers and/or toes (partial syndactyly), kidney (renal) abnormalities, genital malformations, and/or, in some cases, complete fusion of the eyelids (cryptophthalmo...

Froehlich syndrome is a constellation of endocrine abnormalities believed to result from damage to the hypothalamus, a part of the brain where certain functions such as sleep cycles and body temperature are regulated. Froehlich syndrome appears to...

Krabbe's Leukodystrophy is a rare inherited lipid storage disorder caused by a deficiency of the enzyme galactocerebrosidase (GALC), which is necessary for the breakdown (metabolism) of the sphingolipids galactosylceremide and psychosine. Failure ...

Krabbe's Leukodystrophy is a rare inherited lipid storage disorder caused by a deficiency of the enzyme galactocerebrosidase (GALC), which is necessary for the breakdown (metabolism) of the sphingolipids galactosylceremide and psychosine. Failure ...

Krabbe's Leukodystrophy is a rare inherited lipid storage disorder caused by a deficiency of the enzyme galactocerebrosidase (GALC), which is necessary for the breakdown (metabolism) of the sphingolipids galactosylceremide and psychosine. Failure ...

Gangrene facts Gangrene refers to dead or dying body tissue(s) that occur because of inadequate blood supply. There are two major types of gangrene, wet gangrene and dry gangrene. Dry gangrene can result from con...

Giant axonal neuropathy is a rare neuropathy that severely affects the peripheral as well as the central nervous system. The first symptoms appear in early childhood. This disorder is characterized by abnormalities in the peripheral and central ne...

Giant axonal neuropathy is a rare neuropathy that severely affects the peripheral as well as the central nervous system. The first symptoms appear in early childhood. This disorder is characterized by abnormalities in the peripheral and central ne...

Glossitis is a condition characterized by inflammation of the tongue. This inflammation can cause the tongue to become swollen, red, and painful. Glossitis can be caused by a variety of factors, including infections, allergies, nutritional deficie...

Pierre Robin sequence is characterized by an unusually small lower jaw (micrognathia) and downward displacement of the tongue (glossoptosis). Some infants also have an abnormal opening in the roof of the mouth (cleft palate); both the soft and har...

Gaucher disease is a rare, inherited metabolic disorder in which deficiency of the enzyme glucocerebrosidase results in the accumulation of harmful quantities of certain fats (lipids), specifically the glycolipid glucocerebroside, throughout the b...

Glutaricaciduria II is one of the conditions termed organic acidemias. Individuals with these conditions have a deficiency or absence of an enzyme that prevents them from breaking down certain chenicals in the body, resulting the accumulation of s...

Hers disease is a genetic metabolic disorder caused by a deficiency of the enzyme, liver phosphorylase. This enzyme is necessary to break down (metabolize) glycogen, a carbohydrate that is stored in the liver and muscle and used for energy. Defici...

Forbes disease (GSD-III) is one of several glycogen storage disorders (GSD) that are inherited as autosomal recessive traits. Symptoms are caused by a lack of the enzyme amylo-1,6 glucosidase (debrancher enzyme). This enzyme deficiency causes exce...

Andersen disease belongs to a group of rare genetic disorders of glycogen metabolism, known as glycogen storage diseases. Glycogen is a complex carbohydrate that is converted into the simple sugar glucose for the body's use as energy. Glycogen sto...

Gonorrhea is a bacterial infection that is transmitted during sexual activity. Gonorrhea is not transmitted from toilet seats. Women infected with gonorrhea may not have any symptoms. Gonorrhea is treated with an...

Guillain-Barre (gee-YAH-buh-RAY) syndrome is a rare disorder in which your body's immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually ...

Gottron syndrome (GS) is an extremely rare inherited disorder characterized by the appearance of premature aging (progeria), especially in the form of unusually fragile, thin skin on the hands and feet (distal extremities). GS is described as a mi...

Chromosome 10, monosomy 10p is a rare chromosomal disorder in which the end (distal) portion of the short arm (p) of chromosome 10 is missing (deleted or monosomic). The range and severity of symptoms and findings may be variable, depending upon t...

Hashimoto's thyroiditis is also known as Chronic Lymphocytic Thyroiditis, Hashimoto's Thyroiditis, and Chronic Autoimmune Thyroiditis. The thyroid gland gradually stops producing enough hormones to keep the body running normally as a result of Has...

What is cancer? Cancer is a group of many related diseases that begin in cells, the body's basic unit of life. All of the bodies tissues and organs are composed of cells of various types. Normally, cells grow and divide to form new cells i...

Cardiac catheterization (also called cardiac cath or coronary angiogram) is an invasive imaging procedure that tests for heart disease by allowing your doctor to see how well your heart is functioning. During the test, a long, narrow tube, called ...

Cardiac catheterization (also called cardiac cath or coronary angiogram) is an invasive imaging procedure that tests for heart disease by allowing your doctor to see how well your heart is functioning. During the test, a long, narrow tube, called ...

According to the American Heart Association, about 5 million Americans are diagnosed with valvular heart disease each year. What Is Valvular Heart Disease? Heart valve disease occurs when your heart's valves do not work the way the...

Helicobacter pylori (H. pylori) facts Helicobacter pylori (H. pylori) is a bacterium that causes chronic inflammation in the stomach and is a common cause of ulcers worldwide H. pylori causes chronic inflammation (gastriti...

A hematoma is a collection of blood outside of a blood vessel. Symptoms of hematomas depend upon their location and whether adjacent structures are affected by the inflammation and swelling associated with the bleeding. Tr...

Hepatorenal syndrome (HRS) is a form of impaired kidney function that occurs in individuals with advanced liver disease. Individuals with hepatorenal syndrome do not have any identifiable cause of kidney dysfunction and the kidneys themselves are ...

Hereditary spherocytic hemolytic anemia is a rare blood disorder characterized by defects within red blood cells (intracorpuscular) that result in a shortened survival time for these cells. Red blood cells (erythrocytes) normally circulate for a f...

Autosomal recessive hyper IgE syndrome (AR-HIES) is a very rare primary immunodeficiency disorder. Symptoms often become apparent at birth or early during infancy or childhood. The disorder is characterized by the triad of highly elevated levels o...

Horner syndrome is a relatively rare disorder characterized by a constricted pupil (miosis), drooping of the upper eyelid (ptosis), absence of sweating of the face (anhidrosis), and sinking of the eyeball into the bony cavity that protects the eye...

Progeria, or Hutchinson-Gilford progeria syndrome (HGPS), is a rare, fatal, genetic condition of childhood with striking features resembling premature aging. Children with progeria usually have a normal appearance in early infancy. At approximatel...

Bowen Hutterite syndrome is a rare genetic disorder that is apparent at birth (congenital). The disorder is characterized by growth delays before birth (intrauterine growth retardation); failure to grow and gain weight at the expected rate (failur...

Familial lipoprotein lipase (LPL) deficiency is a rare genetic metabolic disorder characterized by a deficiency of the enzyme lipoprotein lipase. Deficiency of this enzyme prevents affected individuals from properly digesting certain fats and resu...

Thyroid disease is particularly common in women of child-bearing age. As a result, it is no surprise that thyroid disease may complicate the course of pregnancy. Frequency varies among different populations and different c...

IBS triggers and prevention facts Foods and drinks that dehydrate the body can trigger constipation in IBS patients. Fatty foods can trigger diarrhea in people with IBS; others may also do so but specific food triggers of di...

Erythrokeratolysis hiemalis is an extremely rare form of ichthyosis that was first described in South Africa but has subsequently been identified in other countries. In such cases, a link to South Africa has been determined. The disorder is charac...

X-linked ichthyosis is a genetic skin disorder that affects males. It is an inborn error of metabolism characterized by a deficiency of the enzyme steroid sulfatase. Under normal conditions, this enzyme breaks down (metabolizes) cholesterol sulfat...

Familial idiopathic basal ganglia calcification (FIBGC) is a rare neurological disorder characterized by the presence of abnormal calcium deposits (calcifications) of unknown cause. Associated symptoms include progressive deterioration of cognitiv...

General DiscussionPediatric cardiomyopathy is a rare heart condition that affects infants and children. Specifically, cardiomyopathy means disease of the heart muscle (myocardium). Several different types of cardiomyopathy exist and the s...

Hyper-IgM Syndrome (HIM) is a rare genetic (primary) immunodeficiency disorder that is typically inherited as an X-linked recessive genetic trait. Symptoms and physical findings associated with the disorder usually become apparent in the first or ...

Apnea is a term used to describe the temporary absence of spontaneous breathing. Infantile apnea occurs in children under the age of one year. Apnea may occur because of neurological impairment of the respiratory rhythm or obstruction of air flow ...

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weak...

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weak...

Weil syndrome, a rare infectious disorder, is a severe form of the bacterial infection caused by Leptospira bacteria known as leptospirosis. Weil syndrome is characterized by dysfunction of the kidneys and liver, abnormal enlargement of the liver ...

Insulin is a hormone that is produced by the beta cells of the pancreas. These cells are scattered throughout the pancreas in small clusters known as the islets of Langerhans. The insulin produced is released into the blood stream and travels thro...

Fetal retinoid syndrome is a characteristic pattern of mental and physical birth defects that results from maternal use of retinoids, the synthetic derivatives of vitamin A, during pregnancy. The most well known retinoid is isotretinoin (Accutane)...

Fetal retinoid syndrome is a characteristic pattern of mental and physical birth defects that results from maternal use of retinoids, the synthetic derivatives of vitamin A, during pregnancy. The most well-known retinoid is isotretinoin (Accutane)...

Jansen type metaphyseal chondrodysplasia is an extremely rare progressive disorder in which portions of the bones of the arms and legs develop abnormally with unusual cartilage formations and subsequent abnormal bone formation at the large (bulbou...

Machado-Joseph Disease (MJD-III), also called spinocerebellar ataxia type III, is a rare, inherited, ataxia (lack of muscular control) affecting the central nervous system and characterized by the slow degeneration of particular areas of the brain...

Joubert syndrome is an autosomal recessive genetic disorder that affects the area of the brain that controls balance and coordination. This condition is characterized by a specific finding on an MRI called a "molar tooth sign" in which the cerebel...

Joubert syndrome is an autosomal recessive genetic disorder that affects the area of the brain that controls balance and coordination. This condition is characterized by a specific finding on an MRI called a "molar tooth sign" in which the cerebel...

Kabuki syndrome is a rare, multisystem disorder characterized by multiple abnormalities including distinctive facial features, growth delays, varying degrees of intellectual disability, skeletal abnormalities, and short stature. A wide variety of ...

Kennedy disease is a rare, X-linked slowly progressive neuro-muscular disorder. Kennedy disease is typically an adult-onset disease, where symptoms occur mainly between the ages of 20 and 50. The disease is characterized by symptoms such as muscle...

Klinefelter syndrome facts Klinefelter syndrome, also known as the XXY condition, is a term used to describe males who have an extra X chromosome in most of their cells. About one of every 500 males has an extra X chromoso...

Laryngeal Papilloma is a rare medical condition in which non-cancerous tumors form along the aerodigestive tract. Laryngeal Papilloma grows inside the voice box, vocal cords, or the air passage from the nose to the lungs. The symptoms include brea...

Madelung's disease is a disorder of fat metabolism (lipid storage) that results in an unusual accumulation of fat deposits around the neck and shoulder areas. Adult alcoholic males are most often affected, although women and those who do not drink...

Cri du chat syndrome (CdCS or 5p-) is a rare genetic disorder in which a variable portion of the short arm of chromosome 5 is missing or deleted (monosomic). Symptoms vary greatly from case to case depending upon the exact size and location of the...

Granuloma annulare is a chronic degenerative skin disorder. The most common form is localized granuloma annulare, which is characterized by the presence of small, firm red or yellow colored bumps (nodules or papules) that appear arranged in a ring...

Chanarin Dorfman syndrome is a rare hereditary disorder of fat (lipid) metabolism. It is characterized by scaly skin (ichthyosis), degeneration of the muscles (myopathy), and abnormal white blood cells with small spaces (vacuoles) filled with fat ...

Liver cancer is a condition that happens when normal cells in the liver become abnormal and grow out of control into cancer. Malignant or cancerous cells that arise out of liver cells are called hepatocellular carcinoma, and cancer that ar...

Paracoccidioidomycosis (PCM) is a chronic infectious tropical disease caused by the fungus Paracoccidioides brasiliensis. The initial infection usually occurs in the lungs, but may also spread to the skin, mucous membranes, and other parts of the ...

Low back pain facts Functions of the low back, or lumbar area, include structural support, movement, and protection of certain body tissues. Pain in the low back can be a result of conditions affecting the bony lumbar spin...

Congenital syphilis is a chronic infectious disease caused by a spirochete (treponema pallidum) acquired by the fetus in the uterus before birth. Symptoms of this disease may not become apparent until several weeks or months after birth and, in so...

Women may not be the only ones who suffer the effects of changing hormones. Some doctors are noticing that their male patients are reporting some of the same symptoms that women experience in perimenopause and menopause. The medical commun...

Noonan syndrome is a common genetic disorder that is typically evident at birth (congenital). The disorder is characterized by a wide spectrum of symptoms and physical features that vary greatly in range and severity. In many affected individuals,...

Osteopetrosis may be inherited as either a dominant or recessive trait and is marked by increased bone density, brittle bones, and, in some cases, skeletal abnormalities. Although symptoms may not initially be apparent in people with mild forms of...

Marcus Gunn phenomenon is a rare genetic disorder that is usually present at birth. It is characterized by the movement of one upper eyelid in a rapid rising motion each time the jaw moves. Other eye abnormalities and vision difficulties may also ...

Menopause is defined as the absence of menstrual periods for 12 months. It is the time in a woman's life when the function of the ovaries ceases. The process of menopause does not occur overnight, but rather is a gradual process. Th...

Menopause is defined as the absence of menstrual periods for 12 months. It is the time in a woman's life when the function of the ovaries ceases. The process of menopause does not occur overnight, but rather is a gradual process. Th...

Menstrual cramps that occur in the absence of a known abnormality or cause are medically referred to as primary dysmenorrhea. Non-drug treatments for menstrual cramps include adequate rest and sleep, regular exercise (especially wal...

Dextrocardia with Situs Inversus is a rare heart condition characterized by abnormal positioning of the heart. In this condition, the tip of the heart (apex) is positioned on the right side of the chest. Additionally, the position of the heart cha...

Megalocornea-mental retardation (MMR) syndrome, otherwise known as Neuhauser syndrome, is an extremely rare genetic disorder characterized by distinctive abnormalities of the eye, several degrees of cognitive impairment, and a wide variety of addi...

Chromosome 18, Monosomy 18p is a rare chromosomal disorder in which all or part of the short arm (p) of chromosome 18 is deleted (monosomic). The disorder is typically characterized by short stature, variable degrees of mental retardation, speech ...

Chromosome 3, Monosomy 3p is a rare chromosomal disorder in which the end (distal) portion of the short arm (p) of chromosome 3 is missing (deleted or monosomic). The range and severity of symptoms and findings may be variable. However, associated...

Morquio syndrome (mucopolysaccharidosis type IV; MPS IV) is a mucopolysaccharide storage disease that exists in two forms (Morquio syndromes A and B) and occurs because of a deficiency of the enzymes N-acetyl-galactosamine-6-sulfatase and beta-gal...

Morquio syndrome (mucopolysaccharidosis type IV; MPS IV) is a mucopolysaccharide storage disease that exists in two forms (Morquio syndromes A and B) and occurs because of a deficiency of the enzymes N-acetyl-galactosamine-6-sulfatase and beta-gal...

Motor neuron disease comprises a group of severe disorders of the nervous system characterized by progressive degeneration of motor neurons (neurons are the basic nerve cells that combine to form nerves). Motor neurons control the behavior of musc...

I-cell disease (mucolipidosis II) is a rare inherited metabolic disorder characterized by coarse facial features, skeletal abnormalities and mental retardation. The symptoms of I-cell disease are similar to but more severe than those of Hurler syn...

Morquio syndrome (mucopolysaccharidosis type IV; MPS IV) is a mucopolysaccharide storage disease that exists in two forms (Morquio syndromes A and B) and occurs because of a deficiency of the enzymes N-acetyl-galactosamine-6-sulfatase and beta-gal...

Mulibrey nanism is an extremely rare autosomal recessive genetic disorder characterized by profound growth delays and distinctive abnormalities of the muscles, liver, brain, and eyes. The acronym MULIBREY stands for (MU)scle, (LI)ver, (BR)ain, and...

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a rare disorder that affects women. It is characterized by the failure of the uterus and the vagina to develop properly in women who have normal ovarian function and normal external genitalia. Wome...

Mulvihill-Smith syndrome is an extremely rare disorder characterized by low birth weight; growth delays leading to short stature (dwarfism); and/or a prematurely aged facial appearance. Other findings may include additional abnormalities of the he...

Nager Syndrome is a rare disorder that may or may not be genetically derived. Major symptoms may include underdevelopment of the cheek and jaw area of the face. Down-sloping of the opening of the eyes, a smaller than normal jaw, lack or absence of...

Infant jaundice is yellow discoloration of a newborn baby's skin and eyes. Infant jaundice occurs because the baby's blood contains an excess of bilirubin (bil-ih-ROO-bin), a yellow pigment of red blood cells. Infant jaundice is a common c...

Ollier disease is a rare skeletal disorder characterized by abnormal bone development (skeletal dysplasia). While this disorder may be present at birth (congenital); it may not become apparent until early childhood when symptoms, such as deformiti...

Ollier disease is a rare skeletal disorder characterized by abnormal bone development (skeletal dysplasia). While this disorder may be present at birth (congenital); it may not become apparent until early childhood when symptoms, such as deformiti...

Oral cancer is a type of cancer that develops in the tissues of the mouth or throat. It can occur in the lips, tongue, gums, floor of the mouth, roof of the mouth, or the inner lining of the cheeks and throat. Oral cancer is often linked to tobacc...

Oral cysts are fluid-filled sacs or pouches that can develop in the mouth. They can occur in various locations, including the gums, lips, tongue, and roof of the mouth. Oral cysts are typically painless and may go unnoticed until they become large...

Oral Kaposi sarcoma is a type of cancer that affects the lining of the mouth and throat. It is caused by a virus called human herpesvirus 8 (HHV-8) and is most commonly seen in individuals with weakened immune systems, such as those with HIV/AIDS....

Oral Myofunctional Disorder (OMD) is a condition that affects the muscles and functions of the mouth and face. It can involve abnormal patterns of muscle movement during activities such as swallowing, speaking, and breathing. OMD can lead to a var...

Oral papilloma is a benign growth or tumor that develops on the mucous membranes in the mouth. It is caused by the human papillomavirus (HPV) and typically appears as a small, painless bump or cluster of bumps. Oral papillomas are usually harmless...

Oral submucous fibrosis (OSMF) is a chronic, progressive condition that affects the mucous membranes in the mouth. It is characterized by the formation of fibrous bands in the oral cavity, which can lead to restricted mouth opening, difficulty in ...

Oral thrush, also known as oral candidiasis, is a fungal infection caused by the overgrowth of Candida albicans in the mouth. It typically appears as white, creamy patches on the tongue, inner cheeks, roof of the mouth, gums, or tonsils. Oral thru...

Hyperoxaluria occurs when you have too much oxalate in your urine. Oxalate is a natural chemical in your body, and it's also found in certain types of food. But too much oxalate in your urine can cause serious problems. Hyperoxaluria can b...

Paget disease of the breast is a form of breast cancer that affects the skin of the nipple. The cause of Paget disease of the breast is poorly understood, but it may be related to tumor cells from other sites in the breast traveling...

Palatal petechiae are small red or purple spots that appear on the roof of the mouth (palate). They are caused by tiny broken blood vessels and are often a sign of trauma or injury to the mouth, such as forceful vomiting, coughing, or oral sex. Pa...

Idiopathic nodular panniculitis is a rare spectrum of skin disorders characterized by single or multiple, tender or painful bumps below the surface of the skin (subcutaneous nodules) that usually lead to inflammation of the subcutaneous layer of f...

Idiopathic nodular panniculitis is a rare spectrum of skin disorders characterized by single or multiple, tender or painful bumps below the surface of the skin (subcutaneous nodules) that usually lead to inflammation of the subcutaneous layer of f...

Parkinson's disease is a progressive, disabling disease that can rob people of the ability to walk and cause other movement problems. There is no known cure, but medications can slow the progress of Parkinson's. Researchers are predicting ...

Parkinson's disease is a progressive nervous system disorder that affects movement. Symptoms start gradually, sometimes starting with a barely noticeable tremor in just one hand. Tremors are common, but the disorder also commonly causes stiffness ...

Pelvic Inflammatory Disease (PID) is an infection of the female reproductive organs, including the uterus, fallopian tubes, and ovaries. It is usually caused by sexually transmitted infections such as chlamydia and gonorrhea, but can also be cause...

Phelan-McDermid syndrome is a rare chromosomal disorder in which a portion of the long arm (q) of chromosome 22 is missing (deleted or monosomic). Although the range and severity of symptoms may vary, Phelan-McDermid syndrome is generally thought ...

Phlebitis refers to inflammation of a vein and it can be caused by any insult to the blood vessel wall, impaired venous flow, or coagulation abnormality. Pain, swelling, redness, and tenderness are some common symptoms of phlebitis....

Phlebitis refers to inflammation of a vein and it can be caused by any insult to the blood vessel wall, impaired venous flow, or coagulation abnormality. Pain, swelling, redness, and tenderness are some common symptoms of phlebitis....

Pierre Robin sequence is characterized by an unusually small lower jaw (micrognathia) and downward displacement of the tongue (glossoptosis). Some infants also have an abnormal opening in the roof of the mouth (cleft palate); both the soft and har...

Pierre Robin sequence is characterized by an unusually small lower jaw (micrognathia) and downward displacement of the tongue (glossoptosis). Some infants also have an abnormal opening in the roof of the mouth (cleft palate); both the soft and har...

Pierre Robin sequence is characterized by an unusually small lower jaw (micrognathia) and downward displacement of the tongue (glossoptosis). Some infants also have an abnormal opening in the roof of the mouth (cleft palate); both the soft and har...

Pilonidal cyst facts Pilonidal cysts are fluid-filled sacs that form at the top of the crease of the buttocks above the sacrum. A painful abscess can form if the cyst and the overlying skin become infected. Pilonidal cysts...

Pinguecula and Pterygium are two common eye conditions that affect the conjunctiva, the thin, transparent membrane that covers the white part of the eye and the inner surface of the eyelids. A Pinguecula is a yellowish, slightly raised bump on the...

Respiratory depression (hypoventilation) is a breathing disorder characterized by slow and ineffective breathing. During a normal breathing cycle, you inhale oxygen into your lungs. Your blood carries the oxygen around your body, deliverin...

Branchio-oculo-facial syndrome (BOFS) is a very rare genetic disorder that is apparent at birth (congenital). As of 2004, only about 50 cases of BOFS had been reported in the medical literature. The symptoms of most BOFS patients include the proli...

Pernicious anemia is a rare blood disorder characterized by the inability of the body to properly utilize vitamin B12, which is essential for the development of red blood cells. Most cases result from the lack of the gastric protein known as intri...

Psoriatic arthritis facts Psoriatic arthritis is a chronic disease characterized by a form of inflammation of the skin (psoriasis) and joints (inflammatory arthritis). Some 10%-15% of people with psoriasis also develop inf...

Psoriatic arthritis is a chronic disease characterized by a form of inflammation of the skin (psoriasis) and joints (inflammatory arthritis). Some 10%-15% of people with psoriasis also develop inflammation of joints (psoriatic arthr...

Pleuropulmonary blastoma (PPB) is a rare childhood cancer occurring in the chest, specifically in the lungs or in the coverings of the lungs called "pleura". PPB occurs almost exclusively in children under the age of approximately 7-8 years and ra...

Acquired neuromyotonia is an inflammatory disorder characterized by abnormal nerve impulses from the peripheral nerves that result in continuous muscle fiber activity. Affected individuals often experience progressive muscle stiffness and cramping...

Recurrent Respiratory Papillomatosis (RRP) is the respiratory condition characterised by the presence of recurrent wart-like growths called papillomas around the vocal cords in the respiratory tract. It is caused by the Human Papill...

Sydenham chorea is a rare neurological disorder characterized by rapid, involuntary, purposeless movements, especially of the face, feet and hands. Additional symptoms may include muscle weakness and emotional or behavioral problems. Sydenham chor...

Familial dysautonomia is a rare genetic disorder of the autonomic nervous system (ANS) that primarily affects people of Eastern European Jewish heritage. It is characterized by diminished sensitivity to pain, lack of overflow tearing in the eyes, ...

Pierre Robin sequence is characterized by an unusually small lower jaw (micrognathia) and downward displacement of the tongue (glossoptosis). Some infants also have an abnormal opening in the roof of the mouth (cleft palate); both the soft and har...

Rothmund-Thomson syndrome is a rare condition that affects many parts of the body, particularly the skin....

Smith-Lemli-Opitz syndrome (SLOS) is a variable genetic disorder that is characterized by slow growth before and after birth, small head (microcephaly), mild to moderate mental retardation and multiple birth defects including particular facial fea...

Rothmund-Thomson syndrome (RTS) is a rare genetic disorder that can affect many parts of the body. The disorder is characterized by distinctive abnormalities of the skin, sparse hair, eyelashes and/or eyebrows, small stature, skeletal and dental a...

Russell-Silver syndrome (RSS) is a rare disorder characterized by intrauterine growth retardation and postnatal growth deficiency along with a handful of common physical characteristics and a range of other symptoms. The wide spectrum of phenotype...

Russell-Silver syndrome (RSS) is a rare disorder characterized by intrauterine growth retardation and postnatal growth deficiency along with a handful of common physical characteristics and a range of other symptoms. The wide spectrum of phenotype...

Sakati syndrome is an extremely rare disorder that belongs to a group of rare genetic disorders known as "Acrocephalopolysyndactyly" (ACPS). All forms of ACPS are characterized by premature closure of the fibrous joints (cranial sutures) between c...

Salivary gland stones, also known as sialolithiasis, are small, hard mineral deposits that form in the salivary glands. These stones can block the flow of saliva from the gland to the mouth, causing pain, swelling, and infection. Salivary gland st...

Short chain acyl-CoA dehydrogenase (SCAD) deficiency is a rare autosomal recessive genetic disorder of fatty acid catabolism belonging to a group of diseases known as fatty acid oxidation disorders (FOD). It occurs because of a deficiency of the s...

Scleroderma is a chronic autoimmune disease that causes the skin and connective tissues to become thickened and hardened. Oral scleroderma specifically refers to the involvement of the mouth and oral cavity in the disease. This can manifest as tig...

Though they're not cancerous, sebaceous cysts can be irritating. A sebaceous cyst is a small lump or bump under the skin. This type of cyst is not cancerous. They are most often found on the face, neck, upper back, and upper chest,...

Shin splints facts Shin splints are a type of "overuse injury" to the legs. The pain is characteristic and located on the outer edge of the mid region of the leg next to the shinbone (tibia). It can be extreme and halt wor...

Sialorrhea, also known as drooling, is the excessive production of saliva that results in saliva spilling out of the mouth. It can be caused by a variety of factors, including neurological conditions, developmental delays, medications, or problems...

Sjogren's Syndrome is a chronic autoimmune disorder in which the body's immune system mistakenly attacks its own moisture-producing glands, leading to symptoms such as dry eyes, dry mouth, and dry skin. It can also affect other parts of the body, ...

Weismann-Netter-Stuhl syndrome is an extremely rare genetic skeletal disorder characterized by the abnormal development of bone (osseousbo dysplasia). Affected individuals exhibit bowing of the long portions (shafts) of the shinbone (tibia) and th...

Smith-Lemli-Opitz syndrome (SLOS) is a variable genetic disorder that is characterized by slow growth before and after birth, small head (microcephaly), mild to moderate mental retardation and multiple birth defects including particular facial fea...

Smith-Lemli-Opitz syndrome (SLOS) is a variable genetic disorder that is characterized by slow growth before and after birth, small head (microcephaly), mild to moderate mental retardation and multiple birth defects including particular facial fea...

Spinal Cord Injury Facts The most common cause of spinal cord injury is trauma. Spinal cord injury is most common in young, white men. Spinal cord injury can be either complete or incomplete. In complete injuries...

Diffuse idiopathic skeletal hyperostosis (DISH), also known as Forestier's disease, affects the ligaments around the spine. Sections of the ligaments turn into bone in this disorder, which is considered to be a form of degenerative arthritis. ...

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weak...

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weak...

Split hand/split foot malformation (SHFM) is a genetic disorder characterized by the complete or partial absence of some fingers or toes, often combined with clefts in the hands or feet. There may also be the appearance of webbing between fingers ...

Split hand/split foot malformation (SHFM) is a genetic disorder characterized by the complete or partial absence of some fingers or toes, often combined with clefts in the hands or feet. There may also be the appearance of webbing between fingers ...

Stomach cancer is an abnormal growth of cells that begins in the stomach. The st...

Stomatitis is a general term for inflammation of the mucous lining of the mouth, which can result in painful sores or ulcers. It can be caused by a variety of factors, including viral or bacterial infections, autoimmune disorders, allergies, or ir...

Subacute cerebellar degeneration (SCD) is characterized by the deterioration of the area of the brain concerned with muscle coordination and balance (the cerebellum). Less frequently, the area involved may include the area connecting the spinal co...

Creutzfeldt-Jakob disease (CJD) is an extremely rare degenerative brain disorder (i.e., spongiform encephalopathy) characterized by sudden development of rapidly progressive neurological and neuromuscular symptoms. With symptom onset, affected ind...

Congenital syphilis is a chronic infectious disease caused by a spirochete (treponema pallidum) acquired by the fetus in the uterus before birth. Symptoms of this disease may not become apparent until several weeks or months after birth and, in so...

Pseudoxanthoma elasticum, PXE, is an inherited disorder caused y mutations in the ABCC6 transporter gene that affects connective tissue in some parts of the body. Elastic tissue in the body becomes mineralized; that is, calcium and other minerals ...

General DiscussionRubinstein-Taybi syndrome is a rare genetic multisystem disorder that affects many organ systems of the body. The group of findings (constellation) associated with this syndrome include growth retardation and delayed bon...

Tetanus, also known as lockjaw, is a serious bacterial infection caused by the bacterium Clostridium tetani. The bacteria usually enter the body through a wound or cut, where they produce a toxin that affects the nervous system, leading to muscle ...

Tetracycline staining refers to a discoloration of the teeth caused by the use of tetracycline antibiotics during tooth development. Tetracycline antibiotics can bind to calcium ions in developing teeth, leading to a yellow or grayish-brown discol...

Central pain syndrome is a neurological disorder caused by damage to the central nervous system (CNS). Common symptoms include pain and loss of sensation, usually in the face, arms and/or legs. Pain is often constant and can be mild, moderate, or ...

Pentalogy of Cantrell is a rare disorder that is present at birth (congenital). Pentalogy of Cantrell is characterized by a combination of birth defects. These birth defects can potentially involve the breastbone (sternum), the muscle that separat...

Pentalogy of Cantrell is a rare disorder that is present at birth (congenital). Pentalogy of Cantrell is characterized by a combination of birth defects. These birth defects can potentially involve the breastbone (sternum), the muscle that separat...

Three M syndrome is an extremely rare genetic disorder characterized by low birth weight, short stature (dwarfism), characteristic abnormalities of the head and facial (craniofacial) area, distinctive skeletal malformations, and/or other physical ...

What are yeast infections? What are commonly known as "yeast" infections are caused by various species of a yeast-like fungus called Candida, particularly the species Candida albicans. Yeast organisms are part of the germs (including bacte...

Tongue thrusting is a swallowing pattern in which the tongue pushes forward against the front teeth when swallowing, rather than pressing up against the roof of the mouth. This can lead to dental issues such as an open bite, speech problems, and d...

Tonsillitis is an inflammation of the tonsils, which are two small glands located at the back of the throat. It is usually caused by a viral or bacterial infection and can result in symptoms such as sore throat, difficulty swallowing, fever, and s...

A tooth abscess is a painful infection that occurs at the root of a tooth or between the tooth and the gum. It is usually caused by bacteria entering the tooth through a cavity, crack, or chip in the tooth. The infection can cause swelling, pain, ...

Tooth discoloration is when the color of the teeth changes from their natural shade to a different color, typically yellow, brown, or gray. This can be caused by a variety of factors, including: 1. Poor oral hygiene: Not brushing and ...

Cervical dystonia, also known as spasmodic torticollis, is a rare neurological disorder characterized by involuntary muscle contractions in the neck that cause abnormal movements and postures of the neck and head. In some cases, these abnormal con...

Esophageal atresia (EA) is a rare birth defect in which the esophagus (the tube that connects the throat with the stomach) does not develop normally. In infants with EA, the esophagus is usually separated into two parts, an upper and lower segment...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Tropical Sprue is a rare digestive disease in which the small intestine's ability to absorb nutrients is impaired (malabsorption). Consequently, nutritional deficiencies and abnormalities in the mucous lining of the small intestine may be present....

Tyrosinemia type I is a rare autosomal recessive genetic metabolic disorder characterized by lack of the enzyme fumarylacetoacetate hydrolase (FAH), which is needed for the final break down of the amino acid tyrosine. Failure to properly break dow...

An underbite is a dental condition in which the lower teeth protrude further out than the upper teeth when the jaw is closed. This misalignment of the teeth can cause issues with chewing, speaking, and overall oral health. Underbites can be caused...

Urethral cancer is a disease in which malignant (cancer) cells form in the tissues of the urethra. The urethra is the tube that carries urine from the bladder to outside the body. In women, the urethra is about 1½ inches long and is...

What is the urethra? The urethra is the opening that allows urine to leave the bladder. In men, the urethra is a thin tube-like structure that starts from the lower opening of the bladder and traverses the entire length of the penis. In wo...

Uterine fibroids facts Uterine fibroids are benign tumors that originate in the uterus (womb). It is not known exactly why women develop uterine fibroids. Most women with uterine fibroids have no symptoms. Howeve...

General DiscussionVACTERL association is a nonrandom association of birth defects that affects multiple median and para-median structures. The term VACTERL is an acronym with each letter representing the first letter of one of the more co...

General DiscussionVACTERL association is a nonrandom association of birth defects that affects multiple median and para-median structures. The term VACTERL is an acronym with each letter representing the first letter of one of the more co...

Clubfoot is a general term used to describe a group of deformities of the ankles and/or feet that are usually present at birth (congenital). The defect may be mild or severe and may affect one or both of the ankles and/or feet. Different forms of ...

Congenital Varicella Syndrome is an extremely rare disorder in which affected infants have distinctive abnormalities at birth (congenital) due to the mother's infection with chickenpox (maternal varicella zoster) early during pregnancy (i.e., up t...

General DiscussionChromosome 22q11.2 deletion syndrome is associated with a range of problems including: congenital heart disease, palate abnormalities, immune system dysfunction including autoimmune disease, low calcium (hypocalcemia) an...

What is a ventricular septal defect (VSD)? A ventricular septal defect (VSD) is a heart malformation present at birth. Any condition that is present at birth can also be termed a "congenital" condition. A VSD, therefore, is a type of conge...

What is a ventricular septal defect (VSD)? A ventricular septal defect (VSD) is a heart malformation present at birth. Any condition that is present at birth can also be termed a "congenital" condition. A VSD, therefore, is a type of conge...

Joubert syndrome is an autosomal recessive genetic disorder that affects the area of the brain that controls balance and coordination. This condition is characterized by a specific finding on an MRI called a "molar tooth sign" in which the cerebel...

Diffuse idiopathic skeletal hyperostosis (DISH), also known as Forestier's disease, affects the ligaments around the spine. Sections of the ligaments turn into bone in this disorder, which is considered to be a form of degenerative arthritis. ...

Lichen sclerosus is a chronic skin disorder that most commonly affects post-menopausal women. However, it is sometimes identified among pre-menopausal women, and, even more rarely, among males. When found in males, the disease is known as balaniti...

Primary intestinal lymphangiectasia (PIL) is a rare digestive disorder characterized by abnormally enlarged (dilatated) lymph vessels supplying the lining of the small intestine. The main symptoms are swelling of the limbs and abdominal discomfort...

Some people with Wallenberg's syndrome have difficulty balancing while walking because they feel like the world is tilting. Wallenberg's syndrome, also called lateral medullary syndrome or Wallenberg syndrome, is a neurological condition...

Weaver Syndrome is characterized by rapid growth. Usually starting before birth (prenatal onset), physical growth and bone development (maturation) can occur more quickly than average. Other symptoms can include increased muscle tone (hypertonia) ...

Weaver Syndrome is characterized by rapid growth. Usually starting before birth (prenatal onset), physical growth and bone development (maturation) can occur more quickly than average. Other symptoms can include increased muscle tone (hypertonia) ...

Weil syndrome, a rare infectious disorder, is a severe form of the bacterial infection caused by Leptospira bacteria known as leptospirosis. Weil syndrome is characterized by dysfunction of the kidneys and liver, abnormal enlargement of the liver ...

Weismann-Netter-Stuhl syndrome is an extremely rare inherited skeletal disorder characterized by the abnormal development of bone (osseous dysplasia). Affected individuals exhibit bowing of the long portions (shafts) of the shinbone (tibia) and th...

Familial eosinophilic cellulitis is a rare skin disorder. It is characterized by raised, red, swollen, and warm areas of skin, in a flame-shaped pattern with associated pain. The exact cause of the disease is unknown. However, bites of spiders, be...

The spinal muscular atrophies (SMAs), are characterized by degeneration of nerve cells (motor nuclei) within the lowest region of the brain (lower brainstem) and certain motor neurons in the spinal cord (anterior horn cells) leading to muscle weak...

Keratosis follicularis, also known as Darier disease, is a rare, genetic skin disorder. Affected individuals develop skin lesions that consist of thickened, rough bumps (papules) or plaques that may also be greasy or have a brown or yellow crust. ...

Wolf-Hirschhorn syndrome is an extremely rare chromosomal disorder caused by a partial deletion (monosomy) of the short arm ("p") of chromosome 4. Major symptoms may include extremely wide-set eyes (ocular hypertelorism) with a broad or beaked nos...

Werner Syndrome is a rare progressive disorder that is characterized by the appearance of unusually accelerated aging (progeria). Although the disorder is typically recognized by the third or fourth decades of life, certain characteristic findings...

X-linked myotubular myopathy (XLMTM) is a rare genetic neuromuscular disorder that is characterized by muscle weakness that can range from mild to profound. Symptoms are often present at birth, but may first develop during infancy or early childho...