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...

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...

Bruxism, also known as teeth grinding, is a condition characterized by the involuntary clenching, grinding, or gnashing of teeth. It can occur during the day or night, but is most commonly associated with nighttime grinding, known as sleep bruxism...

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...

An epidemic is defined as occurring when "new cases of a certain disease, in a given human population during a given time period, substantially exceed what is expected based upon recent experience." Pediatric obesity has reached epidemic proportio...

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder. It is characterized by associated ocular, motor, behavioral, sleep, and language disturbances. The onset is usually abrupt, often severe, and can become chronic....

What is the difference between diabetes insipidus and diabetes mellitus Diabetes insipidus should not be confused with diabetes mellitus (DM), which results from insulin deficiency or resistance leading to high blood glucose, also called b...

What is the difference between diabetes insipidus and diabetes mellitus Diabetes insipidus should not be confused with diabetes mellitus (DM), which results from insulin deficiency or resistance leading to high blood glucose, also called b...

Nephrogenic diabetes insipidus (NDI) is a rare kidney disorder that may be inherited or acquired. NDI is not related to the more common diabetes mellitus (sugar diabetes), in which the body does not produce or properly use insulin. NDI is a distin...

Nephrogenic diabetes insipidus (NDI) is a rare kidney disorder that may be inherited or acquired. NDI is not related to the more common diabetes mellitus (sugar diabetes), in which the body does not produce or properly use insulin. NDI is a distin...

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...

A fibroma is a benign tumor that is composed of fibrous or connective tissue. It can develop in various parts of the body, including the skin, organs, and soft tissues. Fibromas are typically slow-growing and non-cancerous, but they can cause symp...

Fibromyalgia facts Fibromyalgia is a pain syndrome characterized by chronic pain, fatigue, and tenderness to touch. Fibromyalgia is the most common cause of chronic, widespread pain in the United States. Fibromya...

Fox-Fordyce disease is a rare skin disorder that primarily affects women. The disorder is characterized by intense itching especially in the underarm area, the pubic area and around the nipples. In Fox-Fordyce disease abnormalities affecting the a...

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...

Congenital central hypoventilation syndrome (CCHS) is a rare disorder of respiratory control with autonomic nervous system dysregulation (ANSD). The autonomic nervous system is the portion of the nervous system that controls or regulates certain i...

Biotinidase deficiency (BTD) is a treatable, metabolic disorder that is the result of a low concentration, or complete lack, of the enzyme, biotinidase. Biotinidase deficiency is an inherited disorder in which the body is not able to properly proc...

Hydrocephalus is a condition characterized by excessive accumulation of fluid in the brain. Hydrocephalus may be congenital or acquired. Communicating hydrocephalus occurs when cerebrospinal fluid (CSF) can still flow amon...

General DiscussionHypoplastic left heart syndrome is a term used to describe a group of closely related rare heart defects that are present at birth (congenital). The normal heart has four chambers. The two upper chambers, known as atria,...

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...

Infant respiratory distress syndrome is a lung disorder that tends to affect premature infants. Major symptoms include difficulty in breathing and collapsed lungs, potentially requiring mechanical ventilation or positive end-expiratory pressure (P...

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 ...

Insomnia is difficulty falling or staying asleep, the absence of restful sleep, or poor quality of sleep. Insomnia is a symptom and not a disease....

Jarcho-Levin syndrome is a rare genetic disorder characterized by distinctive malformations of bones of the spinal column (vertebrae) and the ribs, respiratory insufficiency, and/or other abnormalities. Infants born with Jarcho-Levin syndrome have...

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...

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder. It is characterized by associated ocular, motor, behavioral, sleep, and language disturbances. The onset is usually abrupt, often severe, and can become chronic....

Kyphosis facts There are three main types of kyphosis: postural, Scheuermann's, and congenital. Most cases of kyphosis do not require any treatment. Physical therapy and exercise are often effective in postural a...

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...

The Mucopolysaccharidoses (MPS Disorders) are a group of rare genetic disorders caused by the deficiency of one of the lysosomal enzymes, resulting in an inability to metabolize complex carbohydrates (mucopolysaccharides) into simpler molecules. H...

The Mucopolysaccharidoses (MPS Disorders) are a group of rare genetic disorders caused by the deficiency of one of the lysosomal enzymes, resulting in an inability to metabolize complex carbohydrates (mucopolysaccharides) into simpler molecules. H...

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...

Narcolepsy is a chronic disease of the central nervous system. The symptoms include excessive daytime sleepiness (EDS), loss of muscle tone (cataplexy), distorted perceptions (hypnagogic hallucinations), inability to move or talk (sleep paralysis)...

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...

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder. It is characterized by associated ocular, motor, behavioral, sleep, and language disturbances. The onset is usually abrupt, often severe, and can become chronic....

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder. It is characterized by associated ocular, motor, behavioral, sleep, and language disturbances. The onset is usually abrupt, often severe, and can become chronic....

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder. It is characterized by associated ocular, motor, behavioral, sleep, and language disturbances. The onset is usually abrupt, often severe, and can become chronic....

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...

Narcolepsy is a neurological sleep disorder characterized by chronic, excessive attacks of drowsiness during the day, sometimes called excessive daytime sleepiness (EDS). Attacks of drowsiness may persist for only a few seconds or several minutes....

If you're a woman, you may be more familiar with the premenstrual syndrome than you'd like to be. But do you know when a problem period indicates that a visit to your doctor is in order? For most women, menstrual cycles last between 21 and...

Problem sleepiness occurs when sleepiness during the day interferes with work or social functioning. Symptoms of problem sleepiness may include difficulty concentrating, falling asleep while driving, or problems with emotional contr...

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...

Sleep apnea is defined as a reduction or cessation of breathing during sleep. The three types of sleep apnea are central apnea, obstructive apnea, and a mixture of central and obstructive apnea. Central sleep apnea is caus...

Smith-Magenis syndrome is characterized by particular facial features, developmental delays, mental retardation and behavioral abnormalities. The facial features include a broad square-shaped face, an abnormally short, broad head (brac...

Smith-Magenis syndrome is characterized by particular facial features, developmental delays, mental retardation and behavioral abnormalities. The facial features include a broad square-shaped face, an abnormally short, broad head (brac...