a circumscribed inflammatory and often suppurating lesion on the skin or an internal mucous surface resulting in necrosis of tissue
<noun.state>
the process of ulcer formation; the process of becoming ulcerated
<noun.process>
Ulceration \Ul`cer*a"tion\, n. [L. ulceratio: cf. F. ulc['e]ration.] (Med.) The process of forming an ulcer, or of becoming ulcerous; the state of being ulcerated; also, an ulcer.
There is no warning of possible clotting or ulceration.
But "there was no signficant difference between the groups in the incidence of gastric ulceration" or stomach ulcers, the report said.