Gastroschisis is a rare congenital disorder in which a defect is present in the wall of the abdomen. Typically there is a small abdominal cavity with herniated abdominal organs that usually appear on the right side of the abdomen. There is no memb...

Malignant large bowel cystadenocarcinoma is quite treatable and frequently cured when it only affects the digestive system. 1. One-stage resection anastomosis, which can be subtotal colectomy or segmental colectomy, w...

An actinic keratosis (ak-TIN-ik ker-uh-TOE-sis) is a rough, scaly patch on your skin that develops from years of exposure to the sun. It's most commonly found on your face, lips, ears, back of your hands, forearms, scalp or neck. Also know...

Classical lissencephaly, also known as lissencephaly type I, is a brain malformation that may occur as an isolated abnormality (isolated lissencephaly sequence [ILS]) or in association with certain underlying syndromes (e.g., Miller-Dieker syndrom...

Alkaptonuria is an inherited condition that causes urine to turn black when exposed to air. Ochronosis, a buildup of dark pigment in connective tissues such as cartilage and skin, is also characteristic of the disorder. This blue-black pigmentatio...

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...

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...

General DiscussionArachnoiditis is a disease characterized by an acute inflammatory stage that occurs in the dura (exterior) and the arachnoid (interior), two of the three membranes that cover and protect the brain, the spinal cord and th...

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....

Arthritis is the swelling and tenderness of one or more joints. The main symptoms of arthritis are joint pain and stiffness, which typically worsen with age. The most common types of arthritis are osteoarthritis and rheumatoid arthritis. O...

Astigmatism is a common eye condition that causes blurred vision due to an irregularly shaped cornea. It occurs when the cornea is curved more in one direction than the other, which causes light to be focused unevenly on the retina. This can cause...

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...

Infectious arthritis is an inflammation of one or more joints that occurs as a result of infection by bacteria, viruses or, less frequently, fungi or parasites. The symptoms of Infectious arthritis depend upon which agent has caused the infection ...

Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina. Bacterial vaginosis is not dangerous, but it can cause disturbing sym...

Kernicterus is a rare neurological disorder characterized by excessive levels of bilirubin in the blood (hyperbilirubinemia) during infancy. Bilirubin is an orange-yellow bile pigment that is a byproduct of the natural breakdown of hemoglobin in r...

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...

Bloom syndrome is a rare genetic disorder characterized by short stature; increased sensitivity to light (photosensitivity); multiple small dilated blood vessels on the face (facial telangiectasia), often resembling a butterfly in shape; immune de...

Blue rubber bleb nevus syndrome (BRBNS) is a rare blood vessel (vascular) disorder that affects the skin and internal organs of the body. Multiple distinctive skin lesions are usually characteristic of this disorder and are often present at birth ...

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 ...

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...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

Maple syrup urine disease (MSUD) is a rare genetic disorder characterized by deficiency of certain enzymes (branched-chain alpha-keto acid dehydrogenase complex) required to breakdown (metabolize) specific amino acids in the body. Because these am...

Breast cancer is the most common cancer in pregnant women and tends to affect women in their mid-30s. Although only about 1 in every 1,000 pregnant women get breast cancer, the disease can be devastating to both the mother and her child -- so it i...

Introduction to Breast Cancer Recurrence Breast cancer can recur at any time, but most recurrences occur in the first three to five years after initial treatment. Breast cancer can come back as a local recurrence (in the treated breast or ...

Introduction to Breast Cancer Recurrence Breast cancer can recur at any time, but most recurrences occur in the first three to five years after initial treatment. Breast cancer can come back as a local recurrence (in the treated breast or ...

Bullous pemphigoid is an uncommon skin disease characterized by tense blisters on the surface of the skin. Occasionally, the inner lining tissue of the mouth, nasal passages, or conjunctivae of the eyes (mucous membrane tissue) can be involved. Th...

Familial articular chondrocalcinosis is a rare inherited metabolic disorder characterized by deposits of calcium pyrophosphate dihydrate crystals (CPPD) in one or more joint cartilages resulting in eventual damage to the joints. Symptoms may devel...

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...

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...

Camptomelic 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; ot...

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 ...

Roussy-Levy Syndrome, also known as hereditary areflexic dystasia, is a rare genetic neuromuscular disorder that typically becomes apparent during early childhood. The disorder is characterized by incoordination, poor judgment of movements (sensor...

CHILD syndrome (an acronym for congenital hemidysplasia with ichthyosiform erythroderma and limb defects) is an inherited disorder, affecting primarily women, that is characterized by ichthyosis-like skin abnormalities and limb defects on one side...

Duchenne muscular dystrophy (DMD) is a rare muscle disorder but it is one of the most frequent genetic conditions affecting approximately 1 in 3,500 male births worldwide. It is usually recognized between three and six years of age. DMD is charact...

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...

Colon cancer Open pop-up dialog box Close Colon cancer Colon cancer Colon cancer can occur in any part of the colon. An examination of your entire colon using a long, flexible tube equipped with a camera (colonoscopy) is one way to detect ...

Colon cancer can occur in any part of the colon. An examination of your entire colon using a long, flexible tube equipped with a camera (colonoscopy) is one way to detect colon cancer and polyps. Colon cancer is a type of cancer that begin...

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...

Adenoid cystic carcinoma (ACC) is a relatively rare form of cancer that most commonly develops in the salivary glands or other regions of the head and neck. In some cases, ACC may arise in other primary sites, such as the skin; the breast; the nec...

Oculocerebral Syndrome with Hypopigmentation is an extremely rare inherited disorder characterized by the lack of normal color (hypopigmentation) of the skin and hair and abnormalities of the central nervous system that affect the eyes and certain...

Cryptococcus is a fungus that is found in soil all over the world, usually in association with bird droppings. Cryptococcus neoformans is the most common Cryptococcus species that causes illness in humans. Cryptococcus gattii, a less common specie...

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...

Cutis laxa is rarely encountered and may occur in several inherited (congenital) forms or come about in the course of another disorder (acquired). It is a connective tissue disorder characterized by skin that is loose (lax), hanging, wrinkled, and...

A cystocele occurs when the wall between a woman's bladder and her vagina weakens and allows the bladder to droop into the vagina. Symptoms of a cystocele include urine leakage and incomplete emptying of the bladder. Cause...

Best vitelliform macular dystrophy is an autosomal dominant genetic form of macular degeneration that usually begins in childhood or adolescence and slowly progresses to affect central vision. The age of onset and severity of vision loss are highl...

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...

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...

Degenerative disc disease and sciatica facts The discs of the spine serve as "cushions" between each vertebral segment. The discs are designed somewhat like a jelly donut. Degeneration (deterioration) of the disc...

Degos disease is an extremely rare disorder in which small and medium sized arteries become blocked (occlusive arteriopathy), restricting the flow of blood to affected areas. Degos disease usually causes characteristic skin lesions that may last f...

Urine tests for diabetes facts Urine tests may be done in people with diabetes to evaluate severe hyperglycemia (severe high blood sugar) by looking for ketones in the urine. Ketones are a metabolic product produced when fat...

Urine tests for diabetes facts Urine tests may be done in people with diabetes to evaluate severe hyperglycemia (severe high blood sugar) by looking for ketones in the urine. Ketones are a metabolic product produced when fat...

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, ...

Dislocated ankle facts An isolated dislocated ankle is a rare injury. Usually, there is an associated fracture of the bones that make up the ankle. The ankle dislocates as a result of a fall, motor-vehicle crash, or sporti...

Brachial plexus palsy, also known as Erb's palsy, is a paralysis or weakness of the arm caused by an injury to one or more nerves that control and supply the muscles of the shoulder and upper extremities (upper brachial plexus). It is more commonl...

Meningiomas are benign, slow-growing tumors, classified as brain tumors, but actually growing in the three protective membranes that surround the brain (meninges). Sometimes they cause thickening or thinning of adjoining skull bones. Meningiomas d...

Trismus-Pseudocamptodactyly Syndrome is a very rare inherited disorder characterized by the inability to completely open the mouth (trismus), causing difficulty with chewing (mastication) and/or the presence of abnormally short muscle-tendon units...

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. ...

Ehlers-Danlos syndrome (EDS) is a group of hereditary connective tissue disorders characterized by defects of the major structural protein in the body (collagen). Collagen, a tough, fibrous protein, plays an essential role in holding together, str...

An ectopic pregnancy is a pregnancy located outside the inner lining of the uterus. Risk factors for ectopic pregnancy include previous ectopic pregnancies and conditions (surgery, infection) that disrupt the normal anatomy of the F...

Ehlers-Danlos syndrome (EDS) is a group of hereditary connective tissue disorders characterized by defects of the major structural protein in the body (collagen). Collagen, a tough, fibrous protein, plays an essential role in holding together, str...

General DiscussionEisenmenger syndrome is a rare progressive heart condition that develops in some individuals with structural malformations of the heart that are present from birth (congenital heart defects). The disorder is characterize...

Encephalitis is an inflammation of the brain. Meningitis is an inflammation of the membranes (called meninges) that surround the brain and spinal cord. Both infections can be caused by bacteria or viruses and rarely a fungus. ...

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...

Epidermal nevus syndromes (ENSs) are a group of rare complex disorders characterized by the presence of skin lesions known as epidermal nevi associated with additional extra-cutaneous abnormalities, most often affecting the brain, eye and skeletal...

The largest part of the brain, the cerebrum, is divided into four paired sections -- the frontal, parietal, occipital, and temporal lobes. Each lobe controls a specific group of activities. The temporal lobe, located on either side of the brain ju...

The largest part of the brain, the cerebrum, is divided into four paired sections -- the frontal, parietal, occipital, and temporal lobes. Each lobe controls a specific group of activities. The temporal lobe, located on either side of the brain ju...

Tuberous sclerosis is a rare genetic multisystem disorder that is typically apparent shortly after birth. The disorder may be characterized by episodes of uncontrolled electrical activity in the brain (seizures); mental retardation; distinctive sk...

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...

Eye allergies, also known as allergic conjunctivitis, are a type of allergic reaction that affects the eyes. Symptoms of eye allergies include redness, itching, burning, tearing, and swelling of the eyes. Eye allergies are usually caused by airbor...

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...

Farsightedness, also known as hyperopia, is a vision condition in which distant objects appear clearly, but close objects appear blurry. It occurs when the eyeball is too short or the cornea has too little curvature, so light entering the eye is n...

Congenital fiber type disproportion (CFTD) is a rare genetic muscle disease that is usually apparent at birth (congenital myopathy). It belongs to a group of muscle conditions called the congenital myopathies that tend to affect people in a simila...

Factor XIII deficiency is a rare, genetic bleeding disorder characterized by a deficiency of clotting factor XIII. Clotting factors are specialized proteins that are essential for the blood to clot properly. Specifically, individuals with factor X...

Formaldehyde is a transitional molecule that participates in a wide range of biological activities. It can be found in a variety of everyday items, including meals. It's also used in medicine to treat a variety of ailments. Formalin is a 40 percen...

Trigeminal neuralgia, also known as tic douloureux, is a disorder of the fifth cranial nerve (trigeminal nerve) characterized by attacks of intense, stabbing pain affecting the mouth, cheek, nose, and/or other areas on one side of the face. The ex...

Frozen shoulder Frozen shoulder occurs when the connective tissue enclosing the joint becomes thickened and tight. Frozen shoulder, also known as adhesive capsulitis, is a condition characterized by stiffness and pain in your shoul...

A prolactinoma is a benign tumor of the pituitary gland (adenoma) that produces an excessive amount of the hormone prolactin. In women, hyperprolactinemia is characterized by irregular menstrual periods (amenorrhea), infertility and production of ...

Ahumada-Del Castillo is a rare endocrine disorder affecting adult females, which is characterized by impairment in the function of the pituitary and hypothalamus glands. Symptoms may include the production of breast milk (lactation) not associated...

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...

Genital herpes is a sexually transmitted disease caused by herpes simplex virus (HSV). HSV causes genital herpes by entering the skin or mucous membranes through microscopic breaks in the skin and mucous membranes. Genital...

Genital warts (HPV) facts Genital warts are caused by infection with a subgroup of the human papillomaviruses (HPVs). Another subgroup of the HPVs that infect the anogenital tract can lead to precancerous changes in the ut...

Gianotti-Crosti Syndrome is a rare skin disease affecting children between the ages of nine months and nine years. Major symptoms may include blisters on the skin of the legs, buttocks and arms. The disorder is usually preceded by a viral infectio...

Giant Cell Arteritis (GCA) is a type of vasculitis, or inflammation of the blood vessels. It is a chronic inflammatory disorder that affects the large and medium-sized arteries, most commonly the temporal arteries. Symptoms of GCA include headache...

Erythrokeratodermia with ataxia (EKDA) is a hereditary disorder of the skin and nervous system (neurocutaneous syndrome) characterized by groups of hard, red plaques that develop during infancy and childhood. When these skin lesions heal, the diso...

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...

General DiscussionGlutaricaciduria 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, resu...

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...

Grover's disease is a rare, transient skin disorder that consists of small, firm, raised red lesions, most often on the skin of the chest and back. Diagnosis of this disorder becomes apparent under microscopic examination when the loss of the "cem...

Growth hormone insensitivity (GHI) is a group of extremely rare genetic disorders in which the body is unable to use the growth hormone that it produces. GHI can be caused by mutations in the growth hormone receptor (GHR) gene or mutations in gene...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Hartnup disease is a rare metabolic disorder inherited as an autosomal recessive trait. It involves an inborn error of amino acid metabolism as well as niacin deficiency. Factors that may precipitate acute attacks of this disorder may include poor...

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 hemolytic uremic syndrome (HUS)? Hemolytic uremic syndrome (HUS) is a disease of two body systems, the blood stream and the kidney. Hemolysis describes the destruction of red blood cells. In hemolytic uremic syndrome, blood within ...

Papular urticaria, usually called hives, is characterized by large numbers of very itchy red bumps (papules) that come and go every few days over a period of a month or so. The bumps are usually between 0.2 and 2 cm. in size and some may develop i...

Adie Syndrome is a rare neurological disorder affecting the pupil of the eye. In most patients the pupil is dilated (larger than normal) and slow to react to light on nearby objects. In some patients, however, the pupil may be constricted (smaller...

Alkaptonuria is a rare genetic metabolic disorder characterized by the accumulation of homogentisic acid in the body. Affected individuals lack enough functional levels of an enzyme required to breakdown homogentisic acid. Affected individuals may...

Carbamoyl phosphate synthetase I deficiency (CPSID) is a rare inherited disorder characterized by complete or partial lack of the carbamoyl phosphate synthetase (CPS) enzyme. This is one of five enzymes that play a role in the breakdown and remova...

Ornithine transcarbamylase (OTC) deficiency is a rare X-linked genetic disorder characterized by complete or partial lack of the enzyme ornithine transcarbamylase (OTC). OTC is one of six enzymes that play a role in the break down and removal of n...

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...

High blood sugar (hyperglycemia) affects people who have diabetes. Several facto...

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...

Lamellar ichthyosis is a rare genetic skin disorder. In lamellar ichthyosis, the skin cells are produced at a normal rate, but they do not separate normally at the surface of the outermost layer of skin (stratum corneum) and are not shed as quickl...

Ichthyosis hystrix, Curth-Macklin type is a rare inherited skin disorder. It is characterized by scaling skin (ichthyosis) ranging from mild to severe. The patches of scaly, thickened skin range from spotty to severe, and may appear on almost any ...

Netherton syndrome is a rare hereditary disorder characterized by scaling skin, hair anomalies, increased susceptibility to atopic eczema (a skin condition that can result in dry, red and flaky skin), elevated IgE levels, and other related symptom...

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...

Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by increased pressure in the fluid surrounding the brain (cerebrospinal fluid). It is also known as pseudotumor cerebri. Symptoms of IIH include headaches, vision ...

Incontinentia Pigmenti (IP) is a rare genetic dermatological disorder affecting the skin, hair, teeth, and central nervous system. Progressive skin changes occur in four stages, the first of which appear in early infancy or can be present at birth...

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 ...

West syndrome is a type of epilepsy characterized by spasms, abnormal brain wave patterns called hypsarrhythmia and sometimes mental retardation. The spasms that occur may range from violent jackknife or "salaam" movements where the whole body ben...

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...

Osteonecrosis, also known as avascular necrosis, is a disease resulting from the temporary or permanent loss of the blood supply to the bones. Without blood, the bone tissue dies and causes the bone to collapse. If the process involves the bones n...

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...

Jock itch facts Jock itch is a very common groin rash. Roughly half of jock itch is due to fungus. The remainder is caused by moisture, irritation, and bacterial overgrowth. Symptoms and signs of jock itch includ...

Dercum's disease is an extremely rare disorder characterized by multiple, painful growths consisting of fatty tissue (lipomas). These growths mainly occur on the trunk, the upper arms and upper legs and are found just below the skin (subcutaneousl...

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 ...

A keloid scar forms from abnormal healing, and usually develops in people 10 to 20 years old. A keloid, or keloid scar, is a kind of overgrown scar, or an overly aggressive healing response to a wound. It's a type of thick, irregul...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Keratosis pilaris (KP) facts Keratosis pilaris is a very common, benign skin disorder that affects adolescents and adults. Keratosis pilaris causes numerous small, rough, tan or red little bumps around hair follicles on th...

Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD) is a rare genetic disorder of fatty acid metabolism that is transmitted as an autosomal recessive trait. It occurs when an enzyme needed to break down certain very long-chain fatty acids is...

Lichen planus facts Lichen planus is a chronic recurrent rash of unknown cause with no established cure. Lichen planus generally affects adults and can involve any portion of the body, but it has a predilection for the wri...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Urticaria pigmentosa is a rare skin disorder that is a localized (cutaneous) form of mastocytosis. Some clinicians suggest that urticaria pigmentosa is the childhood form of mastocytosis. Mast cells are specialized cells of connective tissue that ...

What is male breast cancer? Men possess a small amount of nonfunctioning breast tissue (breast tissue that cannot produce milk) that is concentrated in the area directly behind the nipple on the chest wall. Like breast cancer in women, can...

What is male breast cancer? Men possess a small amount of nonfunctioning breast tissue (breast tissue that cannot produce milk) that is concentrated in the area directly behind the nipple on the chest wall. Like breast cancer in women, can...

Pseudomyxoma peritonei is a rare malignant growth characterized by the progressive accumulation of mucus-secreting (mucinous) tumor cells within the abdomen and pelvis. The disorder develops after a small growth (polyp) located within the appendix...

Pseudomyxoma peritonei is a rare malignant growth characterized by the progressive accumulation of mucus-secreting (mucinous) tumor cells within the abdomen and pelvis. The disorder develops after a small growth (polyp) located within the appendix...

Atypical mole syndrome, also called dysplastic nevus syndrome, is a disorder of the skin characterized by the presence of many mole-like tumors (nevi). Most people have 10-20 moles over their bodies. People with this syndrome often have more than ...

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...

Marfan syndrome is a genetic disorder that affects connective tissue, which is the material between cells of the body that gives the tissues form and strength. Connective tissue is found all over the body and multiple organ systems may be affected...

Marinesco-Sjogren syndrome (MSS) is a rare genetic disorder that affects multiple organ systems of the body. Common symptoms include difficulty coordinating voluntary movements due to degeneration (atrophy) of the cerebellum (cerebellar ataxia), c...

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...

Migraine is a type of headache that is usually characterized by a throbbing or pulsing pain on one side of the head, accompanied by nausea, vomiting, and sensitivity to light and sound. It is a neurological disorder that affects about 12% of the p...

Moebius syndrome is a rare neurological disorder characterized by weakness or paralysis (palsy) of multiple cranial nerves, most often the 6th (abducens) and 7th (facial) nerves. Other cranial nerves are sometimes affected. The disorder is present...

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...

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...

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, ...

Multiple pterygium syndrome is a very rare genetic disorder characterized by minor facial anomalies, short stature, vertebral defects, multiple joints in a fixed position (contractures) and webbing (pterygia) of the neck, inside bend of the elbows...

Myofascial pain syndrome facts Muscle pain, tenderness, and spasm are characteristics of myofascial pain syndrome. Myofascial pain syndrome typically affects muscle in asymmetric areas of the body. The precise ca...

N-acetylglutamate synthetase (NAGS) deficiency is a rare genetic disorder characterized by complete or partial lack of the enzyme N-acetylglutamate synthetase (NAGS). NAGS is one of six enzymes that play a role in the break down and removal of nit...

Listeriosis is a rare but serious infectious disease caused by the bacterium Listeria monocytogenes, which is predominantly transmitted to humans through the consumption of contaminated food. Clinical syndromes associated with listeriosis include ...

Neuropathic pain is a pain condition that’s usually chronic. It’s usually caused by chronic, progressive nerve disease, and it can also occur as the result of injury or infection. If you have chronic neuropathic pain, it can fl...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Nonketotic hyperglycinemia is an inborn error of metabolism characterized by the accumulation of large amounts of the amino acid glycine in blood, urine and, particularly, the cerebrospinal fluid (CSF). The metabolic block occurs in the conversion...

Norrie disease is a rare X-linked disorder that occurs due to errors or disruption (mutations) of the NDP gene. All males are affected by loss of vision present at birth or shortly thereafter. Additional symptoms may occur in some case...

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...

Optic neuritis is an inflammation of the optic nerve, which is the nerve that carries visual information from the eye to the brain. Symptoms of optic neuritis include sudden vision loss, pain in the eye, and color vision changes. Optic neuritis is...

General DiscussionRetroperitoneal fibrosis is a rare inflammatory disorder in which abnormal formation of fiber-like tissue (fibrosis) occurs behind the membrane that lines the cavity of the abdomen (peritoneum). This abnormal tissue grow...

Overactive bladder (OAB) facts Overactive bladder is an involuntary and sudden contraction of the muscle in the wall of the urinary bladder. Overactive bladder can also result in urinary incontinence, otherwise termed urge...

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...

Penile cancer is a disease in which malignant (cancer) cells form in the tissues of the penis. The penis is a rod-shaped male reproductive organ that passes sperm and urine from the body. It contains two types of erectile tissue (spongy ti...

Penile cancer is a disease in which malignant (cancer) cells form in the tissues of the penis. The penis is a rod-shaped male reproductive organ that passes sperm and urine from the body. It contains two types of erectile tissue (spongy ti...

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....

Photokeratitis is a painful eye condition caused by exposure to ultraviolet (UV) radiation. It is sometimes referred to as "snow blindness" or "welder's flash." Symptoms of photokeratitis include redness, tearing, pain, and temporary vision loss. ...

Cholinergic urticaria is a relatively common disorder of the immune system characterized by an immediate skin reaction (hypersensitivity) to heat, emotional stress, and/or exercise. Symptoms of the disorder include the appearance of distinctive sm...

Cholinergic urticaria is a relatively common disorder of the immune system characterized by an immediate skin reaction (hypersensitivity) to heat, emotional stress, and/or exercise. Symptoms of the disorder include the appearance of distinctive sm...

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...

Pineal cysts are benign (non-cancerous) fluid-filled sacs located in the region of the brain that contains the pineal gland. Small pineal cysts (.5 cm or smaller) are common occurrences, often found incidentally on routine neurological exams. Smal...

Placenta previa is the attachment of the placenta to the wall of the uterus in a location that completely or partially covers the uterine outlet (opening of the cervix). Bleeding after the 20th week of gestation is the main symptom ...

Polycystic ovary syndrome  Polycystic ovary syndrome is a disorder involving infrequent, irregular or prolonged menstrual periods, and often excess male hormone (androgen) levels. The ovaries develop numerous small collections of flui...

Prader-Willi syndrome (PWS) is a genetic multisystem disorder characterized during infancy by lethargy, diminished muscle tone (hypotonia), feeding difficulties, and poor weight gain. In childhood, features of this disorder include short stature, ...

Prader-Willi syndrome (PWS) is a genetic multisystem disorder characterized during infancy by lethargy, diminished muscle tone (hypotonia), feeding difficulties, and poor weight gain. In childhood, features of this disorder include short stature, ...

General DiscussionWolff-Parkinson-White (WPW) syndrome is a rare congenital heart disorder involving irregularities in the electrical system of the heart. In individuals with WPW syndrome, an abnormal alternate electrical pathway (accesso...

Acquired Pure Red Cell Aplasia is a rare bone marrow disorder characterized by an isolated decline of red blood cells (erythrocytes) produced by the bone marrow. Affected individuals may experience fatigue, lethargy, and/or abnormal paleness of th...

Reye's syndrome is a rare and severe illness affecting children. Reye's syndrome is associated with viral infection and aspirin use. Patients with Reye's syndrome present with vomiting and mental-status changes. ...

General DiscussionRomano-Ward syndrome is an inherited heart (cardiac) disorder characterized by abnormalities affecting the electrical system of the heart. The severity of Romano-Ward syndrome varies greatly from case to case. Some indiv...

What is the rotator cuff? The rotator cuff is the group of four tendons that stabilize the shoulder joint. The tendons hook up to the four muscles that move the shoulder in various directions. There are four muscles whose tendons f...

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

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...

Sandhoff disease is a lipid storage disorder characterized by a progressive deterioration of the central nervous system. The clinical symptoms of Sandhoff disease are identical to Tay-Sachs disease. Sandhoff disease is an autosomal recessive genet...

General DiscussionPhocomelia syndrome (PS) is a rare birth defect that causes severe birth defects, especially of the upper limbs. The bones of the arms, and in some cases other appendages, may be extremely shortened and even absent. The ...

Scabies is an itchy, highly contagious skin disease caused by an infestation by the itch mite Sarcoptes scabiei. Direct skin-to-skin contact is the mode of transmission. A severe and relentless itch is the predominant symp...

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...

SHORT syndrome is a condition in which affected individuals have multiple birth defects in different organ systems. The term SHORT is an acronym with each letter representing one of the common findings in affected persons:(S)= short st...

Chordomas are very rare primary bone tumors that can arise at almost any point along the axis of the spine from the base of the skull to the sacrum and coccyx (tailbone). The incidence of chordoma in the general U.S. population is about 8 per 10,0...

Spinal headaches are a fairly common complication in those who undergo a spinal tap (lumbar puncture) or spinal anesthesia. Both procedures require a puncture of the membrane that surrounds the spinal cord and, in the lower spine, the lumbar and s...

Reflex sympathetic dystrophy syndrome (RSDS), also known as complex regional pain syndrome, is a rare disorder of the sympathetic nervous system that is characterized by chronic, severe pain. The sympathetic nervous system is that part of the auto...

Syphilis is a sexually transmitted disease (STD) caused by an infection with bacteria known as Treponema pallidum. Like other STDs, syphilis can be spread by any type of sexual contact. Syphilis can also be spread from an infected mother to the fe...

General DiscussionBuerger's disease, also known as thromboangiitis obliterans, is a rare disorder that, in most cases, affects young or middle-aged male cigarette smokers. It is characterized by narrowing or blockage (occlusion) of the ve...

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...

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...

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. It is most commonly spread through contact with infected cat feces, but can also be spread through contaminated food or water, or from mother to baby during pregnancy. Symptom...

Trichorhinophalangeal syndrome type II (TRPS2), also known as Langer-Giedion syndrome, is an extremely rare inherited multisystem disorder. TRPS2 is characterized by fine, thin hair; unusual facial features; progressive growth retardation resultin...

What is typhoid fever? What is the history of typhoid fever? Typhoid fever is an acute illness associated with fever that is most often caused by the Salmonella typhi bacteria. It can also be caused by Salmonella paratyphi, a related bacte...

Argininosuccinic aciduria is a rare inherited disorder characterized by deficiency or lack of the enzyme argininosuccinate lyase (ASL). Argininosuccinate lyase is one of six enzymes that play a role in the breakdown and removal of nitrogen from th...

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...

Porphyria cutanea tarda (PCT) is a type of porphyria in which affected individuals are sensitive to sunlight. Exposed skin shows abnormalities that range from slight fragility of the skin to persistent scarring and disfiguration. Due to fragility ...

Porphyria cutanea tarda (PCT) is a type of porphyria in which affected individuals are sensitive to sunlight. Exposed skin shows abnormalities that range from slight fragility of the skin to persistent scarring and disfiguration. Due to fragility ...

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...

Vaginitis is inflammation of the vagina. Symptoms of vaginitis include vaginal pain or discomfort, itching, discharge, and odor. Pain with urination or during sexual intercourse is also common. Vaginitis may be due to infe...

Best vitelliform macular dystrophy is an autosomal dominant genetic form of macular degeneration that usually begins in childhood or adolescence and slowly progresses to affect central vision. The age of onset and severity of vision loss are highl...

Vitiligo is a disease in which the pigment cells of the skin, melanocytes, are destroyed in certain areas. Vitiligo results in depigmented, or white, patches of skin in any location on the body. Vitiligo can be focal and l...

Alopecia areata is a disorder characterized by loss of hair. Sometimes, this means simply a few bare patches on the scalp. In other cases, hair loss is more extensive. Although the exact cause is not known, this is thought to be an autoimmune diso...

Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD) is a rare genetic disorder of fatty acid metabolism that is transmitted as an autosomal recessive trait. It occurs when an enzyme needed to break down certain very long-chain fatty acids is...

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. ...

Prader-Willi syndrome (PWS) is a genetic multisystem disorder characterized during infancy by lethargy, diminished muscle tone (hypotonia), feeding difficulties, and poor weight gain. In childhood, features of this disorder include short stature, ...

The WAS-related disorders are a spectrum of conditions affecting the immune system that are caused by mutations in the WAS gene. These disorders include Wiskott-Aldrich syndrome, X-linked thrombocytopenia and X-linked congenital neutropenia. The W...

Waardenburg syndrome is a genetic disorder that may be evident at birth (congenital). The range and severity of associated symptoms and findings may vary greatly from case to case. However, primary features often include distinctive facial abnorma...

MCT8-specific thyroid hormone cell transporter deficiency (THCT deficiency) is an inherited disorder that is characterized by severe mental retardation, an impaired ability to speak, diminished muscle tone (hypotonia), and/or movement abnormalitie...

L1 syndrome is an inherited, X-linked disorder occurring in males that primarily affects the nervous system. The disease is mainly characterized by hydrocephalus (increased fluid in the center of the brain), spasticity of the lower limbs (muscle s...

Xeroderma pigmentosum (XP) is a group of rare inherited skin disorders characterized by a heightened reaction to sunlight (photosensitivity) with skin blistering occurring after exposure to the sun. In some cases, pain and blistering may occur imm...