Agoraphobia is a fear of being outside or otherwise being in a situation from which one either cannot escape or from which escaping would be difficult or humiliating. Like other phobias, agoraphobia often goes unreported, probably b...

Borderline personality disorder is a personality disorder characterized by consistently problematic ways of thinking, feeling, and interacting, impulsivity, negative self-image and fear of abandonment, leading to difficulties with interpersonal re...

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...

General DiscussionThe word "neurasthenia" is a term that has fallen into disuse among psychiatrists in the United States and Australia. It remains in use in the United Kingdom. Where it is used, it covers a wide spectrum of symptoms inclu...

Wolfram syndrome is the inherited association of childhood-onset diabetes mellitus and progressive-onset optic atrophy. All people affected by Wolfram syndrome have juvenile-onset diabetes mellitus and degeneration of the optic nerve (optic atroph...

Eating disorders are serious conditions related to persistent eating behaviors that negatively impact your health, your emotions and your ability to function in important areas of life. The most common eating disorders are anorexia nervosa, bulimi...

Pancreatic neuroendocrine neoplasms (pNENs) are an increasingly common group of malignancies that arise within the endocrine tissue of the pancreas. Endocrine tissue is specialized tissue that contains hormone-secreting cells. These cells secrete ...

Epilepsy is a central nervous system (neurological) disorder in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations and sometimes loss of awareness. Anyone can develop epilepsy. Epilepsy affec...

Generalized anxiety disorder (GAD) is a mood disorder that is characterized by multiple and/or nonspecific worries that interfere with the person's life in some way. The most common anxiety disorders are specific phobias. Besides ge...

Histidinemia is a rare hereditary metabolic disorder characterized by a deficiency of the enzyme histidase, which is necessary for the metabolism of the amino acid histidine. The concentration of histidine is elevated in the blood. Excessive amoun...

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...

Hypoglycemia is the clinical syndrome that results from low blood sugar. The symptoms of hypoglycemia can vary from person to person, as can the severity. Classically, hypoglycemia is diagnosed by a low blood sugar with symptoms that resolve when ...

Androgen insensitivity refers to an inability of the body to respond properly to male sex hormones (androgens) produced during pregnancy. This occurs because of a change (mutation) in a gene involved in the production of the protein inside cells t...

Macular degeneration facts The macula is in the center of the retina, the light-sensitive layer of tissue at the back of the eye. The macula is responsible for central vision (straight-ahead vision). Degeneration of the macula occur...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

What is mitral valve prolapse? Mitral valve prolapse (also known as "click murmur syndrome" and "Barlow's syndrome") is the most common heart valve abnormality. The condition is slightly more prevalent in women than in men. The mitral valv...

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...

Familial hypophosphatemia is a rare inherited disorder characterized by impaired transport of phosphate and often altered vitamin-D metabolism in the kidneys. In addition, phosphate may not be well-absorbed in the intestines. The hypophosphatemia ...

Premature ovarian failure — also known as primary ovarian insufficiency — is a loss of normal function of your ovaries before age 40. If your ovaries fail, they don't produce normal amounts of the hormone estrogen or release eggs regul...

Premenstrual dysphoric disorder (PMDD) can be considered to be a severe form of premenstrual syndrome (PMS), with symptoms that interfere with daily activities and functioning. PMDD occurs in 3% to 8% of menstruating women. ...

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...

Sick building syndrome is believed by some to be an illness caused by unknown agents in buildings. Sick building syndrome is a controversial subject because many experts do not think it is a true syndrome. Sick building sy...