Two circulation problems, two kinds of ulcer

The venous vs arterial ulcers difference comes down to which direction of blood flow has failed. Arteries carry oxygen-rich blood down to the leg and foot. Veins carry used blood back up to the heart.

A venous ulcer forms when blood cannot get out of the leg well. An arterial ulcer forms when not enough blood can get in. The two can look similar at a glance, but the care for one can be wrong, or even harmful, for the other.

What a venous ulcer usually looks like

Venous ulcers are the more common of the two. Weak valves in the leg veins let blood pool, pressure builds and fluid leaks into the tissue until the skin breaks down.

  • Where: the lower leg, most often around the inner ankle
  • Shape: shallow, with uneven edges
  • Wound bed: red, often with a yellow film, and moist
  • Drainage: moderate to heavy
  • Skin nearby: swollen, with brown or reddish staining, often dry, itchy or thickened
  • Feeling: aching and heaviness that tends to ease when the leg is raised
  • Foot: usually warm, with pulses that can be felt

See the page on venous leg ulcers for more.

What an arterial ulcer usually looks like

Arterial ulcers come from narrowed or blocked arteries, a condition called peripheral artery disease. Tissue starved of oxygen breaks down, often after a minor bump or rub that would normally heal.

  • Where: toes, between the toes, the heel, the outer ankle and other spots over bone
  • Shape: round with sharp, even edges, as if punched out
  • Wound bed: pale, gray or black, and dry
  • Drainage: little or none
  • Skin nearby: thin, shiny and hairless
  • Feeling: often very painful, worse at night or with the leg raised, and eased by hanging the foot over the bed
  • Foot: cool, with weak or absent pulses

The guide to peripheral artery disease and foot wounds explains the underlying condition.

Why the difference changes care

The cause decides the direction of treatment.

  • Compression. Steady pressure from wraps or stockings is the core of venous ulcer care because it helps blood leave the leg. On a leg with poor arterial flow, the same pressure can reduce the blood supply further. The guide to what compression therapy is explains this.
  • Leg position. Raising the legs eases venous swelling but often worsens arterial pain.
  • Restoring blood flow. An arterial ulcer generally cannot close until more blood reaches it, so a vascular specialist is often asked to evaluate.

How clinicians tell them apart

Appearance gives clues, not an answer. The treating clinician combines your history, an exam and often testing:

  1. Questions about leg pain with walking, night pain, past blood clots, varicose veins, diabetes and smoking
  2. An exam of pulses, skin temperature, color, swelling and staining
  3. An ankle-brachial index (ABI), which compares blood pressure at the ankle with the arm
  4. Toe pressures or ultrasound studies of the arteries or veins when more detail is needed

The guide to circulation tests before compression describes these tests.

When a wound is both, or neither

Some people have vein disease and artery disease in the same leg. These are called mixed ulcers, and their care is adjusted to the amount of arterial flow. The page on arterial and mixed wounds covers them.

Other leg and foot wounds are neither. Diabetic foot ulcers, pressure injuries, wounds from inflammatory conditions and some skin cancers can resemble vascular ulcers. A wound that does not behave as expected deserves another look at the diagnosis.

What to report and when to call 911

Tell the treating clinician promptly about:

  • Pain that is increasing, or new pain at night or at rest
  • Toes or skin turning dark, blue or black
  • Spreading redness, warmth, swelling, odor or fever
  • Numb, cold or discolored toes while wearing compression

Call 911 if a leg or foot suddenly becomes cold, pale, numb or severely painful, or for chest pain or sudden shortness of breath.

How Gateway helps sort it out

Gateway arranges visits with partner clinicians across Greater St. Louis and the Metro East. The treating clinician determines the cause of the wound and writes the plan. We coordinate the circulation testing that is ordered, handle vascular and specialist referral coordination, and keep your primary care office informed about circulation and vascular health findings.

To ask about a leg or foot wound, call 314-325-0126 or send a request for care.

Common questions

Can I tell which kind of ulcer I have by looking at it?

You can notice clues, such as where the wound is, how much it drains and what eases the pain. But appearance alone is not reliable. Mixed disease is common, and several other conditions look similar. Treatment that helps one type can harm the other, so a clinician should examine the leg and decide whether circulation testing is needed.

Is one type more serious than the other?

Both need care. An arterial ulcer is generally treated with more urgency because it signals that the foot is not getting enough blood, which puts the limb at risk. A venous ulcer is usually less of a threat to the limb, but it can be large, uncomfortable and prone to returning.

Do varicose veins mean I will get a venous ulcer?

No. Many people have varicose veins and never develop an ulcer. They do show that some vein valves are not working well, so mention them to a primary care clinician. Pay closer attention if you also have ankle swelling, brown staining of the skin, itching or a past blood clot.

Does diabetes cause venous or arterial ulcers?

Diabetes does not cause vein disease, but it raises the risk of artery disease, so it makes arterial and mixed ulcers more likely. It also causes its own kind of wound through nerve damage. A person with diabetes can have more than one cause at work, which is why clinicians check both feeling and blood flow.

Related pages

General information to help you talk with your own clinician. It is not medical advice, and the treating clinician makes every clinical decision. For a medical emergency, call 911.

Updated October 2026