What is Ulcer?
[[Image:ULCERCELLULITIS1.JPG|thumb|[[Diabetes mellitus|Diabetic]] foot ulcer]] An '''ulcer''' is a kind of open [[wound]]. Ulcers can be on surfaces of the body. They can be on [[skin]]. They can be [[mucous membrane]]s like the surface of the stomach or inside the mouth. Ulcers start when the top layer (surface) of skin or mucous membrane is damaged. The top layer [[death|dies]]. When it dies, the skin or mucous membrane opens. This leaves an open sore called an ulcer. Ulcers can be from [[infection]] with germs. Ulcers can be from pressure on a part of the skin. Ulcers can be from substances that will burn skin or mucous membranes. [[Peptic ulcer]]s are sometimes from burning by the acid in the [[stomach]]. Ulcers can be from [[cancer]]. Ulcers can be from diseases of [[blood vessel]]s. If not enough [[blood]] goes to a body part, it can get an ulcer. [[Stress]] can also sometimes cause ulcers. Ulcers are often very painful. {{biology-stub}} [[Category:diseases]]