Clinical Definitions Library Search this library for definitions of clinical terms as well as their related Yale Medicine specialists, fact sheets, and other content. Browse the full list See the full list of keyword definitions below.
Acne is a common skin condition characterized by the appearance of pimples, blackheads, whiteheads, and cysts on the skin, primarily on the face, chest, and back. It occurs when hair follicles become clogged with oil and dead skin cells, leading to inflammation and sometimes infection.
Acne scars are the result of inflammation within the dermis brought on by acne. They are characterized by changes in skin texture, such as depressions or raised areas, and can vary in size, shape, and color. Acne scars can be caused by various factors, including the severity of acne, delayed treatment, or picking at acne
Acoustic neuroma, also known as vestibular schwannoma, is a benign, slow-growing tumor that develops on the vestibulocochlear nerve, which is responsible for hearing and balance. The tumor can cause hearing loss, ringing (and other sounds) in the ears (tinnitus), and balance problems. Acoustic neuroma may lead to more severe complications if left untreated.
Acquired bone marrow failure syndromes are a group of disorders characterized by the inability of the bone marrow to produce sufficient blood cells, leading to anemia, increased risk of infections, and bleeding complications. These syndromes can result from various causes, such as exposure to radiation, pesticides, viral infection, or immune disorders.
Acquired generalized lipodystrophy (AGL) is a rare medical condition characterized by the progressive loss of adipose tissue, leading to a lack of body fat, insulin resistance, and complications related to fat metabolism. It usually occurs during childhood or adolescence and can result from various causes, including autoimmune diseases or infections.
Acromegaly is a rare hormonal disorder characterized by the excessive production of growth hormone, leading to abnormal growth of bones and soft tissues in the hands, feet, and face. It is usually caused by a benign tumor in the pituitary gland called a pituitary adenoma.
Acromioclavicular (AC) joint injury, also known as AC joint separation, is a condition where the ligaments connecting the collarbone (clavicle) to the shoulder blade (scapula) are damaged or torn. This injury often occurs due to a direct blow to the shoulder or a fall on an outstretched arm, resulting in pain, swelling, and limited range
Acromioclavicular (AC) joint repair is a surgical procedure performed to treat injuries or conditions affecting the acromioclavicular joint, which connects the collarbone (clavicle) to the shoulder blade (scapula). The surgery aims to restore stability, function, and range of motion in the shoulder.
Actinic cheilitis, also known as solar cheilitis, is a precancerous condition characterized by inflammation and damage to the lips, primarily the lower lip, caused by prolonged exposure to ultraviolet (UV) radiation from the sun. It presents as rough, scaly patches or dry, cracked lips that do not heal.