DEFINITION Dementia isn’t a specific disease. Instead, dementia describes a group of symptoms affecting memory, thinking and social abilities severely enough to interfere with daily functioning. Dementia indicates problems with at least two brain functions, such as…
DEFINITION Kidney cysts are round pouches of fluid that form in the kidneys. Kidney cysts can be associated with serious disorders that may impair kidney function. But more commonly, kidney cysts are a type called simple kidney cysts — noncancerous…
DEFINITION Jock itch (tinea cruris) is a fungal infection that affects the skin of your genitals, inner thighs and buttocks. Jock itch causes an itchy, red, often ring-shaped rash in these warm, moist areas of your body. Jock itch gets…
DEFINITION Jellyfish stings are relatively common problems for people swimming, wading or diving in seawaters. The long tentacles trailing from the jellyfish body can inject you with venom from thousands of microscopic barbed stingers. Jellyfish stings vary greatly in severity.…
DEFINITION Dandruff is a common chronic scalp condition marked by flaking of the skin on your scalp. Although dandruff isn’t contagious and is rarely serious, it can be embarrassing and sometimes difficult to treat. The good news…
DEFINITION An inguinal hernia occurs when soft tissue — usually part of the membrane lining the abdominal cavity (omentum) or part of the intestine — protrudes through a weak point in the abdominal muscles. The resulting bulge can be painful,…
DEFINITION Jet lag, also called jet lag disorder, is a temporary sleep disorder that can affect anyone who quickly travels across multiple time zones. Jet lag is caused when your body’s internal clock or circadian rhythms, which tell your body…
DEFINITION Itchy skin is an uncomfortable, irritating sensation that makes you want to scratch. Also known as pruritus (proo-RIE-tus), itchy skin may be the result of a rash or another condition, such as psoriasis or dermatitis. Or itchy skin may…
DEFINITION Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep and mood issues. Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain processes pain signals. Fibromyalgia is commonly thought of as a…
DEFINITION Iron deficiency anemia is a common type of anemia — a condition in which blood lacks adequate healthy red blood cells. Red blood cells carry oxygen to the body’s tissues. As the name implies, iron deficiency anemia is due…
DEFINITION Inherited metabolic disorders refer to different types of medical conditions caused by genetic defects — most commonly inherited from both parents — that interfere with the body’s metabolism. These conditions may also be called inborn errors of metabolism. Metabolism…
DEFINITION Inflammatory breast cancer is a rare type of breast cancer that develops rapidly, making the affected breast red, swollen and tender. Inflammatory breast cancer occurs when cancer cells block the lymphatic vessels in skin covering the breast, causing the…