 [ Symptoms ] have lump on gums that doesnt go away stays full of pus stays red and swollen can be painful what is this [ Disease ] i am not sure what that is but it sounds very unpleasant i would suggest you see a dentist for an examination the bump you are describing could be anything from a skin ulcer to an abscessed tooth to an oral cancer a dentist can evaluate the situation and tell you what you are dealing with he or she also will either provide appropriate treatment or refer you for medical treatment i wish i could offer you something more specific but unfortunately it is not possible to diagnose your problem without a physical exam i wish you the best of luck