Arterial vs. Venous Leg Ulcers: How to Tell

Arterial and venous leg ulcers look similar to most people and are treated in nearly opposite ways. The fastest way to tell them apart is location and pain: a venous ulcer usually sits on the inner ankle, weeps fluid, and feels better when you put the leg up. An arterial ulcer usually sits on the toes, heel, or outer ankle, stays dry, and hurts more when you elevate it.

That difference decides whether compression is the treatment or the hazard, which is why it matters far more than it sounds.

September is Vascular Disease Awareness Month. This article is written for patients living with a wound that will not close, for the family members helping manage it, and for anyone who has been handed a dressing plan and wants to understand the reasoning behind it. Lumi, our 24/7 chatbot, is at the bottom right of every page on mcbdme.com if you have a question as you read.

The quick answer

• Venous ulcers are the most common type of leg ulcer. They appear around the inner ankle, have irregular sloping edges, produce a lot of drainage, ache rather than stab, and improve when the leg is elevated. Compression is the core treatment.
• Arterial ulcers appear on the toes, between the toes, on the heel, or on the outer ankle. They look punched out with sharp edges, stay dry, hurt severely, and feel worse when the leg is elevated and better when it hangs down.
• The pulse check is a fast clue. Weak or absent pulses in the foot point arterial. Present pulses point venous, though the pulse exam alone does not settle it.
• Mixed ulcers exist and are the hardest to manage, because the leg has both problems at once.
• Diabetic foot ulcers are a third category, usually on the sole of the foot under pressure points, and often painless because of neuropathy.
• The test that decides the plan is an ankle-brachial index. Compression on an arterial or mixed ulcer without knowing that number is a real risk.

Everything below explains how each one presents and why the treatment diverges.

The six-point comparison

Two of those rows do most of the work. Where it sits and what makes the pain better will separate the majority of cases before anyone touches a Doppler.

Venous ulcers, the common one

The large majority of leg ulcers are venous. Cleveland Clinic describes venous (stasis) ulcers as the most common type of vascular ulcer, and notes they tend to form near the ankle.

The mechanism is straightforward. Valves inside the leg veins are supposed to stop blood from sliding back down between heartbeats. When those valves fail, pressure builds in the lower leg veins, fluid and blood components leak into the surrounding tissue, and the skin around the ankle slowly becomes fragile. Eventually a minor knock, a scratch, or nothing identifiable at all opens a wound that the tissue no longer has the resources to close.

Signs that usually show up before the ulcer does:

• Swelling that is worse by evening and better after a night's sleep
• Brown or rust-colored staining around the ankle, from iron left behind by leaked blood
• Skin that feels hard, tight, or woody just above the ankle
• Itching, flaking, or an eczema-like rash on the lower leg
• Visible varicose veins
• A heavy, aching feeling after standing

Why compression is the treatment. The underlying problem is pressure in the wrong direction. Graduated compression, firmest at the ankle and easing as it goes up the leg, counteracts it directly. That is not a comfort measure, it is the therapy. Wounds treated with adequate compression close faster than wounds treated with dressings alone, and compression after healing is what keeps them from coming back.

Our compression therapy page covers the garment side of this, and our measuring guide walks through how a proper fitting is done.

Arterial ulcers, the dangerous one

Arterial ulcers are less common and more serious. The problem is not fluid pooling, it is oxygen not arriving. Narrowed arteries deliver too little blood for the tissue to maintain itself, and the areas farthest from the heart go first.

That is why the locations are so distinctive. Toes, the tips of toes, the web spaces between them, the heel, the outer ankle bone, and anywhere a shoe or a bed rubs. These are the pressure points and the end of the supply line at the same time.

The presentation:

• Deep and sharply outlined, often described as looking punched out of the skin
• Dry, with little or no drainage, and often a hard dark crust
• Very painful, disproportionate to the size of the wound
• Worse when elevated, better when the leg hangs down, because gravity is doing work the arteries cannot
• On a cool, pale, hairless foot with thin shiny skin and thick slow-growing nails
• With weak or absent pulses at the top of the foot and behind the inner ankle

Why compression is the wrong instinct here. Compression works by squeezing fluid out of the leg. On a limb that is already short on inflow, adding external pressure reduces what little blood is getting in. A wound that was static can get larger, and healthy tissue at the margins can begin to break down. We laid out the full picture in Who Should Not Wear Compression Socks.

The real treatment for an arterial ulcer is restoring blood flow. That means a vascular assessment, and often a procedure to open or bypass the blocked segment. Dressings protect the wound while that happens. They do not heal it on their own. The Society for Vascular Surgery is a useful patient-level reference on what that workup involves.

Mixed ulcers, where it gets complicated

Plenty of people have both problems. Venous valve failure and arterial narrowing share risk factors and both become more common with age, so a leg with a long history of swelling can also have quietly narrowing arteries.

A mixed ulcer often looks venous, sits in a venous location, and then does not respond to standard venous care. That non-response is frequently the first clue.

This is where the ankle-brachial index earns its keep. A widely used general clinical convention looks like this, though the prescribing clinician always makes the final call for a given patient:

• ABI above 0.80: standard compression is generally appropriate
• ABI 0.50 to 0.80: reduced or modified compression, under clinical supervision
• ABI below 0.50: compression generally avoided, vascular evaluation first

We covered how that test works, and why a number above 1.40 cannot be trusted, in Ankle-Brachial Index: The Test Before Compression.

The practical point for a patient: if a leg ulcer has been treated for weeks without improvement, asking whether the arterial side has been checked is a fair question.

Diabetic foot ulcers are a third thing

These get grouped with the other two and behave differently from both.

A diabetic foot ulcer is usually neuropathic in origin. Nerve damage removes the pain signal that would normally make you shift your weight or take the shoe off. Pressure concentrates in the same spot day after day, a callus forms, and the tissue underneath breaks down before anyone feels anything.

The distinguishing features:

• On the sole of the foot, most often under the ball of the foot or the big toe joint, sometimes on the heel
• Ringed by thick callus
• Often painless, which is exactly why they are found late
• On a foot that may be warm with good pulses, if the problem is purely nerve-related

Many diabetic foot ulcers are mixed, with a neuropathic and an arterial component together. The CDC advises checking your feet every day, even if they feel fine, using a mirror or a family member's help to see the soles. That daily check remains the single most useful habit for catching these early.

The treatment here is offloading, taking pressure off the spot so the tissue can rebuild. That is the entire logic behind therapeutic footwear, and Medicare covers it for qualifying patients. We wrote about how that benefit works in Diabetic Shoes and Medicare, and about the design choices that matter in The Science Behind the Shoe.

What MCB DME does, and what we do not

Being clear about this saves people a phone call.

We do not diagnose or treat wounds. We are not a wound care center. The decision about what kind of ulcer you have, and what dressing plan it needs, belongs to your physician, your podiatrist, or your wound care team.

What we do is supply and fit the equipment that supports the plan once it is made:

• Compression garments in the class your clinician specifies, properly measured and fitted, including flat knit where the limb shape requires it
• Lymphedema and arterial pumps, delivered and set up in the home with technician training
• Therapeutic footwear and inserts for offloading
• Coordination with your prescriber when arterial status needs confirming before a garment goes on

If you arrive with an order that already includes an ABI value, we can usually move straight to fitting. If it does not, we will ask, and that is the whole reason for asking.

Red flags: call today

Wound care is usually a slow patient process. These are the exceptions.

• A sudden cold, pale, painful leg or foot, often with numbness. This can signal an acute blockage and is an emergency. Go to the emergency department.
• Spreading redness, warmth, or swelling around the wound, particularly with fever or chills. That suggests infection reaching beyond the wound.
• A foul smell, or tissue turning black.
• A sharp increase in pain in a wound that had been stable.
• Any new wound on the foot of a person with diabetes, however small and however painless.

Frequently asked questions

How can I tell if my leg ulcer is arterial or venous at home?

You can form a reasonable suspicion from location and what relieves the pain. Inner ankle, wet, better with the leg up, points venous. Toes or heel, dry, worse with the leg up, points arterial. You cannot confirm it at home, and the ankle-brachial index is what settles it.

Are arterial ulcers more serious than venous ones?

Generally yes. Venous ulcers are more common and more disruptive to daily life, but arterial ulcers signal that a limb is not receiving enough blood, which carries a higher risk to the limb itself. Both deserve prompt attention.

Can I use compression socks on a leg ulcer?

Only if a clinician has confirmed the ulcer is venous and the arterial supply is adequate. On an arterial or mixed ulcer, compression chosen without that information can make the wound worse.

How long does a leg ulcer take to heal?

Venous ulcers treated with adequate compression often close over weeks to a few months, though larger or long-standing ones take longer. Arterial ulcers typically will not close at all until blood flow is improved, which is why the vascular assessment comes first rather than after a trial of dressings.

Why does my ulcer keep coming back?

For venous ulcers, recurrence is usually about what happens after healing. The vein problem does not go away when the wound closes, and ongoing compression is what holds the result. Stopping the garments once the skin looks fine is the most common reason a healed ulcer reopens.

Key takeaways

• Location and pain relief separate most arterial ulcers from most venous ones. Inner ankle and better with elevation points venous. Toes, heel, or outer ankle and worse with elevation points arterial.
• Venous ulcers are the common type and compression is the core treatment, not an accessory to it.
• Arterial ulcers signal inadequate blood supply. They need a vascular assessment, and compression is avoided or heavily modified.
• Mixed ulcers are real, they often look venous, and failure to improve on standard care is the usual clue.
• Diabetic foot ulcers sit on the sole, hide under callus, and are often painless. Offloading is the treatment.
• The ankle-brachial index is what turns a guess into a plan.

Next steps

MCB DME is a Medicare-enrolled DMEPOS supplier in Hawthorne, NJ. We serve patients across northern New Jersey and New York, including Rockland County. Once your clinician has determined what kind of wound you are dealing with, we handle the equipment side: properly fitted compression, arterial and lymphedema pumps set up in your home, and therapeutic footwear.

If you have an order in hand and want to get it moving, see our compression therapy options, read about our arterial pump program, or call (973) 553-0777. You can also reach the team here, or ask Lumi, our 24/7 chatbot, at the bottom right of any page.

This article is for general education and is not medical advice. A wound on your leg or foot needs to be evaluated by a clinician.