Arterial vs Venous Ulcers: How to Tell Them Apart
Both arterial and venous ulcers are chronic lower-extremity wounds that cause significant morbidity and share overlapping risk factors, but they arise from opposite vascular problems. Arterial ulcers reflect tissue ischemia from inadequate inflow (peripheral arterial disease), whereas venous ulcers reflect chronic venous insufficiency and ambulatory venous hypertension. The core axis separating them is perfusion: an arterial ulcer occurs in a poorly perfused, pulseless, painful limb, while a venous ulcer occurs in a well-perfused limb with intact pulses but venous stasis changes.
How to tell them apart
| Feature | Arterial Ulcer | Venous Ulcer |
|---|---|---|
| Location | Distal—toes, heel, lateral malleolus, and pressure points | Medial malleolus (the gaiter area) |
| Appearance | Punched-out and deep, with a pale or necrotic base and well-defined edges | Shallow, with irregular borders and a red, granulating base |
| Pain | Severe; worse with elevation and relieved by dependency | Mild to moderate; improved with elevation |
| Surrounding skin | Pale, shiny, hairless, atrophic, and cool | Hyperpigmentation, lipodermatosclerosis, edema, and stasis dermatitis |
| Pulses | Diminished or absent | Normal |
| Associated findings | Claudication, rest pain, and ABI <0.9 | Varicose veins, leg swelling, and a history of DVT |
| Treatment | Revascularization, wound care, and cardiovascular risk factor modification | Compression therapy, wound care, and treatment of the underlying venous insufficiency |
The reasoning
Anchor first on pulses and pain behavior. Diminished or absent pulses in a cool, hairless, atrophic limb with a deep, punched-out distal ulcer point firmly to an arterial (ischemic) etiology—confirm with an ABI <0.9 and look for claudication or rest pain. In contrast, a shallow ulcer over the medial malleolus with a granulating base, surrounded by hyperpigmentation, lipodermatosclerosis, and edema, in a limb with normal pulses, is venous. Use the pain–position relationship as a discriminator: arterial pain worsens with elevation (gravity can no longer aid inflow) and improves with dependency, whereas venous ulcer discomfort improves with elevation as venous congestion drains. The ABI arbitrates ambiguous cases and, critically, must be checked before applying compression—the mainstay of venous ulcer therapy—because compression can be dangerous in the ischemic, low-ABI limb.
Key tests
- Ankle-brachial index (ABI): reduced (<0.9) with arterial ulcers reflecting peripheral arterial disease—and typically <0.4 in critical limb ischemia—whereas it is normal with venous ulcers.
- Peripheral pulse examination: pulses are diminished or absent in arterial disease but normal (2+) in venous disease; grade dorsalis pedis and posterior tibial pulses at the bedside.
- Buerger's test and capillary refill: elevation pallor followed by dependent rubor and prolonged capillary refill (>3 seconds) indicate severe arterial insufficiency, while both are normal in venous ulcers.
- Venous duplex ultrasound: demonstrates venous reflux/insufficiency or prior DVT underlying a venous ulcer; unremarkable in a purely arterial ulcer.
What they share
- Both are chronic ulcers of the lower extremity that require dedicated wound care
- Both occur in patients with vascular risk factors and can be painful to some degree
- Both are diagnosed largely through location, appearance, and bedside vascular examination
Pitfalls
- Applying compression therapy—the correct treatment for venous ulcers—to a patient with unrecognized arterial disease can worsen ischemia; always confirm adequate arterial inflow (ABI) first.
- Mixed arterial-venous ulcers exist; a patient may have both peripheral arterial disease and venous insufficiency, so normal-appearing pulses do not fully exclude arterial contribution.
- Assuming all painful ulcers are arterial—venous ulcers can also be uncomfortable; use the elevation/dependency pain pattern and pulse status rather than pain alone.
- Forgetting to elicit the underlying cause: a venous ulcer should prompt evaluation for varicose veins or prior DVT, while an arterial ulcer signals systemic atherosclerosis requiring cardiovascular risk modification.
Practice this the way the exam tests it — on branching cases where your decisions shape the patient.