Abnormal paleness of the skin and mucous membranes, particularly noticeable in the face. Pallor is not always a symptom of disease. It may be due to a deficiency of the skin pigment melanin that may affect people who spend very little time in daylight. It is also a feature of albinism. In addition, pallor may be caused by constriction of small blood vessels in the skin, which may occur in response to shock, severe pain, injury, heavy blood loss, or fainting. Disorders that cause pallor include anaemia, pyelonephritis, kidney failure, and hypothyroidism. Lead poisoning is a rare cause.


Online Medical Dictionary: Your essential reference to over 5000 medical terms.