These two types of leg ulcers look similar — but treating one like the other can make things dramatically worse. Here's how to tell them apart.
Not all leg ulcers are the same — and treating them as if they were can cause serious harm. At ASG Foot & Ankle Specialists, one of the most important things we do when evaluating a leg ulcer is determine its type. Venous and arterial ulcers require completely different — and in some ways opposite — treatments.
Applying compression therapy to an arterial ulcer, for example, can restrict blood flow and worsen the wound dramatically. Getting the diagnosis right is not just important — it's essential.
| Feature | Venous Ulcer | Arterial Ulcer |
|---|---|---|
| Cause | Poor venous return — blood pools in legs | Poor arterial flow — not enough blood reaching tissue |
| Location | Inner ankle, lower leg (gaiter area) | Toes, heels, bony prominences, between toes |
| Wound appearance | Shallow, irregular edges, sloping borders | Deep, punched-out, well-defined edges |
| Wound bed | Red/pink granulation or yellow slough | Pale, grey, or necrotic (black) tissue |
| Drainage | Moderate to heavy | Minimal or none |
| Pain | Mild to moderate; improves with elevation | Severe; worsens with elevation, improves hanging down |
| Surrounding skin | Brown discoloration, varicose veins, swelling | Pale, shiny, hairless, cool to touch |
| Pulses | Normal foot pulses | Weak or absent foot pulses |
| ABI | Normal (> 0.8) | Low (< 0.8) |
| Prevalence | ~70% of leg ulcers | ~10–15% of leg ulcers |
| Key treatment | Compression therapy | Vascular intervention to restore blood flow |
| Compression safe? | ✓ Yes — essential | ✗ No — can be dangerous |
Chronic venous insufficiency — damaged vein valves allow blood to pool in the lower legs, increasing pressure and causing fluid to leak into tissue, leading to skin breakdown.
Peripheral artery disease (PAD) — atherosclerosis narrows the arteries supplying the legs, starving tissue of oxygen and nutrients. Even minor trauma can cause an ulcer that won't heal.
Approximately 15–20% of leg ulcers have both venous and arterial components — called mixed etiology ulcers. These are the most challenging to treat because compression therapy is needed for the venous component but must be used cautiously due to the arterial disease.
Mixed ulcers require specialist evaluation. Modified compression (lower pressure) may be used if ABI is between 0.6–0.8, but only under close supervision. Never apply full compression to a patient with significant arterial disease.
Learn the warning signs of poor circulation in the feet and legs.
Poor Circulation Signs →Learn why early treatment of venous ulcers is so important.
Venous Ulcer Treatment →Venous ulcers are caused by poor venous return (blood pooling in the legs) and are typically located on the inner ankle, shallow, with irregular edges and heavy drainage. Arterial ulcers are caused by poor arterial blood flow (not enough blood reaching the tissue) and are typically located on the toes, heels, or bony prominences, deep with punched-out edges, minimal drainage, and very painful. Treatment is completely different — compression therapy for venous, vascular intervention for arterial.
Correct diagnosis is critical because the treatments are opposite. Venous ulcers require compression therapy to improve venous return. Arterial ulcers require improved blood flow — and compression therapy in an arterial ulcer can be dangerous, further restricting blood flow and worsening the wound. Applying the wrong treatment can cause serious harm.
Diagnosis involves clinical examination (wound location, appearance, surrounding skin), ankle-brachial index (ABI) measurement to assess arterial blood flow, and duplex ultrasound to evaluate venous and arterial circulation. An ABI below 0.8 indicates significant arterial disease. A podiatrist or vascular specialist can perform these assessments and determine the correct diagnosis and treatment plan.
Correct diagnosis is the foundation of effective leg ulcer treatment. Our board-certified podiatrists perform comprehensive vascular assessments and develop individualized treatment plans. Three locations in the South Chicago suburbs.