An ulcer is a discontinuity or break in a bodily membrane that impedes the organ of which that membrane is a part from continuing its normal functions. Common forms of ulcers recognized in medicine include:

• Ulcer (dermatology), a discontinuity of the skin or a break in the skin.
  • Pressure ulcers, also known as bedsores
  • Genital ulcer, an ulcer located on the genital area
  • Ulcerative dermatitis, a skin disorder associated with bacterial growth often initiated by self-trauma
  • Anal fissure, A.K.A an ulcer or tear near the anus or within the rectum
  • Diabetic foot ulcer, a major complication of the diabetic foot
• Corneal ulcer, an inflammatory or infective condition of the cornea
• Mouth ulcer, an open sore inside the mouth.
  • Aphthous ulcer, a specific type of oral ulcer also known as a canker sore
• Peptic ulcer, a discontinuity of the gastrointestinal mucosa (stomach ulcer)
• Venous ulcer, a wound thought to occur due to improper functioning of valves in the veins
• Stress ulcer, located anywhere within the stomach and proximal duodenum
• Ulcerative sarcoidosis, a cutaneous condition affecting people with sarcoidosis
• Ulcerative lichen planus, a rare variant of lichen planus
• Ulcerative colitis, a form of inflammatory bowel disease (IBD).
• Ulcerative disposition, a disorder or discomfort that causes severe abdominal distress, often associated with chronic gastritis