An ulcer is a sore that develops on the skin or mucous membrane.


An ulcer is a sore that develops on the skin or mucous membrane. It starts with the death (necrosis) and peeling away of surface layers of tissue, but also always affects deeper structures. The causes include, e.g. prolonged pressure, reduced blood flow, pathogens and cancer. Preventive measures against pressure sores are recommended.


  • Location:
    • Skin and gastro-intestinal tract
    • All external and internal body surfaces
    • Edges of heart valves
    • See also stomach ulcer, mouth ulcers
  • Topical skin defect
    • Sloughy deposits of dead cell materials at base of ulcer
  • Skin ulcer can expose deeper anatomical structures:
    • Sinews
    • Muscles
    • Maybe even bone


  • Bleeding
  • Perforation in gastro-intestinal tract
  • Malignant change
  • Blood poisoning (sepsis)
  • Delayed healing or lack of healing
  • Unattractive scars after healing

Causes and treatment


  • Pressure ulcer, pressure sore or bedsore
    • Areas upon which body lies, e.g. sacrum and seat bone or heels
    • Constricting, rigid bandages, e.g. plaster cast
    • Risk: undernourishment, confinement to bed
  • Venous ulcer or leg ulcer (ulcus cruris)
    • Varicose veins on calves: skin usually breaks open just above the inside of the ankle joint
  • Bad circulation
    • Peripheral arterial occlusive disease: ulcers caused by reduction in blood flow (e.g. “smoker’s leg”)
    • Diabetes: impaired circulation in the smallest blood vessels, affects sensitive nerves (“diabetic foot”)
  • Ulcers caused by pathogens
  • Ulcers caused by malignant tumours
  • Other causes

Further treatment by your doctor / in hospital

Possible tests
  • Physical examination
  • Ultrasound (sonography)
  • X-ray (bones affected?)
Possible therapies
  • Remove the cause, relieve pressure
  • Preventive measures (see below)
  • Wound care
  • Surgery to treat wound, if necessary

What can I do myself?

  • Conscientious sun protection (clothing, hat, glasses, sunblock)
  • Healthy lifestyle
    • Balanced diet, normal weight
    • Regular exercise
    • Don’t smoke, drink alcohol in moderation
    • Reduce stress, sleep enough
  • Prevention if at risk of pressure ulcer
    • Check mattress and chair ergonomics
    • Optimise diet
    • Confinement to bed: change position regularly (to relieve pressure)
    • Regular skin care

When to see a doctor?

  • Wounds/skin defects
    • Inflamed, festering wounds
    • Non-healing wounds of all kinds
    • Deeper anatomical structures are visible
  • Skin change doesn't disappear, gets bigger
  • Sensory disturbances in the foot/leg
  • Pain and difficulty when walking
  • Abdominal pain and stomach ache (regularly)



Exclusion of liability

CSS offers no guarantee for the accuracy and completeness of the information. The information published is no substitute for professional advice from a doctor or pharmacist.