ULCER BIOL 1
An ulcer is a skin or mucous membrane disease or sore caused by the progressive breakdown of surface
epithelial tissue. An ulcer can be superficial or deep, extending into the skin or other underlying tissue. An
ulcer features a sunken floor or crater surrounded by strongly defined edges that are occasionally raised
above the adjacent surface. The most common sign of an ulcer is pain.
Infection, improper blood circulation, nerve injury, trauma, nutritional changes such as thiamine or other
vitamin deficiencies, and cancer are the most common causes of ulcers. Bacterial diseases such as TB and
syphilis can result in ulcers on any surface of the body. Any infection beneath the skin, such as a boil or
carbuncle, has the potential to burst through the skin's surface and develop an inflammatory ulcer. The
sluggish circulation of blood in the skin causes ulcers on the legs of people with varicose veins. Diabetics
may develop foot or toe ulcers after losing feeling in those locations owing to nervous-system impairment.
In immobile or bedridden people, a bedsore, also known as a decubitus ulcer, develops on the skin of the
back.