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 Depersonalization-derealization disorder occurs when you persistently or repeatedly have the feeling that you’re observing yourself from outside your body or you have a sense that things around you aren’t real, or both. Feelings of depersonalization and derealization can be…
DEFINITION Delayed ejaculation — sometimes called impaired ejaculation — is a condition in which it takes an extended period of sexual stimulation for a man to reach sexual climax and release semen from the penis (ejaculate). Some men with delayed…
DEFINITION Dermatomyositis (dur-muh-toe-my-uh-SY-tis) is an uncommon inflammatory disease marked by muscle weakness and a distinctive skin rash. Dermatomyositis affects adults and children alike. In adults, dermatomyositis usually occurs from the late 40s to early 60s. In children,…
DEFINITION Depression is a mood disorder that causes a persistent feeling of sadness and loss of interest. Also called major depression, major depressive disorder or clinical depression, it affects how you feel, think and behave and can lead to a…
DEFINITION Diabetes insipidus (die-uh-BEE-teze in-SIP-uh-dus) is an uncommon disorder characterized by intense thirst, despite the drinking of fluids (polydipsia), and the excretion of large amounts of urine (polyuria). In most cases, it’s the result of your body not properly producing,…
DEFINITION Kleptomania (klep-toe-MAY-nee-uh) is the recurrent failure to resist urges to steal items that you generally don’t really need and that usually have little value. Kleptomania is a serious mental health disorder that can cause much emotional pain to you…
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 Dermatographia is a condition also known as skin writing. When people who have dermatographia lightly scratch their skin, the scratches redden into a raised wheal similar to hives. These marks usually disappear within 30 minutes. The…
DEFINITION Dengue (DENG-gey) fever is a mosquito-borne disease that occurs in tropical and subtropical areas of the world. Mild dengue fever causes high fever, rash, and muscle and joint pain. A severe form of dengue fever, also called dengue hemorrhagic…
DEFINITION Diabetic hyperosmolar (hi-pur-oz-MOE-lur) syndrome is a serious condition caused by extremely high blood sugar levels. The condition most commonly occurs in people with type 2 diabetes. It’s often triggered by illness or infection. As a result…
DEFINITION Keratoconus (ker-uh-toe-KOH-nus) occurs when your cornea — the clear, dome-shaped front surface of your eye — thins and gradually bulges outward into a cone shape. A cone-shaped cornea causes blurred vision and may cause sensitivity to light and glare.…