Anorexia

An eating disorder characterized by loss of appetite or total aversion to food. Anorexia nervosa is characterized by a distortion of body image and intense fear of gaining weight, causing emaciation and a lack of menstruation among girls and women, and extreme eating...

Anterior

Pertaining to being in front of another structure – toward the front of the body. Anterior pituitary: The front portion of the pituitary, a small gland in the head called the master gland. Hormones secreted by the anterior pituitary influence growth, sexual...

Antibodies

Part of the immune system, antibodies are proteins produced by white blood cells that circulate in the blood looking for and attaching to foreign proteins and toxins to neutralize them. Antibodies are a type of protein made by plasma cells (a type of white blood cell)...

Antigen

Antigens are capable of causing the production of antibodies and may or may not have an allergic reaction. An Antigen is a substance that causes the immune system to make a specific immune response. An antigen may be a foreign substance from the environment such as...

AO

Adult onset: occurring in adulthood. Adult onset as in patients with growth hormone deficiency occurring in adulthood. Also referring to adult onset diseases such as type 2 diabetes.

Apnea

The absence of breathing. Sleep apnea is a common sleep disorder characterized by brief interruptions of breathing during sleep. Episodes usually last 10 seconds or more and occur repeatedly throughout the night. People with sleep apnea will partially awaken as they...