A leg ulcer is an open wound that doesn’t heal within a few weeks, and its appearance varies depending on the cause. The most common type, a venous leg ulcer, typically looks like a shallow, irregularly shaped wound near the inner ankle, often sitting on skin that has turned brownish-orange. Other types have distinctly different features, and knowing what to look for can help you identify what you’re dealing with.
Venous Leg Ulcers
Venous ulcers account for the majority of leg ulcers and develop when blood doesn’t flow back up from the legs efficiently. They appear most often on the inner leg between the ankle and the calf, an area sometimes called the “gaiter zone” because it’s where a boot gaiter would sit.
The wound itself is shallow with irregular but well-defined borders. The base is often covered in a yellowish-cream material called slough, which is dead tissue, rather than the healthy pink tissue you’d see in a wound that’s healing well. The surrounding skin is one of the biggest visual giveaways: it often has brown-orange speckles or patches caused by iron deposits left behind when red blood cells leak from damaged veins. The skin may also look dry, flaky, and inflamed, particularly around the inner ankle.
In long-standing cases, the lower leg can take on a distinctive “inverted champagne bottle” shape. The skin and fat tissue around the ankle become hardened and tight while the calf above remains its normal size. Varicose veins are frequently visible nearby, and the leg may appear swollen, especially by the end of the day. You might also notice small white patches of scarred skin called atrophie blanche scattered around the ulcer.
Arterial Ulcers
Arterial ulcers look noticeably different from venous ones. They develop when blood flow to the leg is restricted, usually due to narrowed arteries, and they tend to appear on the toes, heels, tops of the feet, and bony prominences rather than on the inner calf.
The classic arterial ulcer has a “punched out” appearance, as if a hole punch cut a neat circle into the skin. The edges are sharply defined, and the wound base is pale or grayish rather than pink, reflecting the poor blood supply. In more severe cases, the base may contain black, dry necrotic tissue. The surrounding skin often looks shiny, tight, and hairless. These ulcers are typically painful, especially at night or when the legs are elevated.
One useful visual clue involves the color of the foot. When the leg hangs down, the foot may turn a deep, dusky red. When you lift the leg up, that redness fades quickly and the foot goes pale. This color shift, called dependent rubor, signals poor arterial circulation and is sometimes mistaken for an infection.
Diabetic Foot Ulcers
Diabetic ulcers most commonly form on the sole of the foot, particularly under the ball of the foot and the heel, where pressure is greatest during walking. Nerve damage from diabetes means you may not feel the ulcer developing, so it’s often discovered visually rather than by pain.
A diabetic ulcer typically has punched-out edges surrounded by a thick ring of callused skin. This callus buildup is one of the most distinctive visual markers. The wound base can range from pink granulation tissue in milder cases to exposed tendon or bone in severe ones. The edges may appear white and soggy if moisture has been trapped against the skin. Surrounding skin can be red, warm, and swollen, particularly if infection has set in.
Pressure Ulcers on the Legs
Pressure ulcers develop where sustained pressure cuts off blood flow to the skin, and on the lower body they most often appear over the heels, ankles, and outer knees. Their appearance depends on how far they’ve progressed.
- Stage 1: The skin is still intact but has a persistent red area that doesn’t turn white when you press on it. On darker skin tones, this may appear as a patch that looks different in color or texture from the surrounding area.
- Stage 2: The top layers of skin have broken open, creating a shallow pink or red wound that may look like a blister or a scrape.
- Stage 3: The wound extends deeper into the fat layer beneath the skin. You may see yellowish dead tissue in the base, and the wound can have a foul smell.
- Stage 4: The deepest stage, where muscle, tendon, or even bone may be visible at the bottom of the wound.
Signs the Wound Is Infected
Any leg ulcer can become infected, and the visual changes are important to recognize. An infected ulcer often produces green or foul-smelling discharge. The skin surrounding the wound becomes increasingly red, swollen, and warm to the touch. On darker skin tones, the redness may be harder to spot, so look for increased swelling, warmth, and a change in the color of the discharge.
Inside the wound, you may notice the tissue looks dark red and bleeds easily when touched, rather than the healthy pale pink of normal healing tissue. An increase in slough (cream or yellow material) or the appearance of black, hard, dry tissue over the wound base also suggests things are moving in the wrong direction.
Skin Changes That Appear Before an Ulcer Forms
Leg ulcers rarely appear out of nowhere. In venous disease, the skin gives warning signs for months or even years before an ulcer opens. The earliest changes are itchy, dry, flaky patches on the inner ankle that look like eczema. The skin may develop reddish-brown discoloration that gradually darkens as more iron pigment accumulates.
Over time, the skin becomes thicker, harder, and tighter. It may feel woody to the touch. The ankle area can shrink as the tissue tightens while the calf stays normal, creating that champagne-bottle shape. At this stage the skin is extremely fragile. Even a minor bump or scratch can open a wound that refuses to heal, becoming a full ulcer.
Less Common Ulcers With Distinctive Looks
Some leg ulcers don’t fit neatly into the categories above. Pyoderma gangrenosum, a rare inflammatory condition, produces an ulcer that looks dramatically different from vascular ulcers. It starts as a red bump or blister that rapidly breaks down into a painful, expanding wound. The most distinctive feature is the border: ragged, overhanging (the edge extends out over the wound like a cliff), and purple or violet in color. The ulcer is extremely painful and grows quickly, sometimes within days. This type of ulcer can be mistaken for an infection but doesn’t respond to antibiotics.
How to Tell What Type You Have
Location is often the first clue. An ulcer on the inner lower leg between the ankle and calf points toward venous disease. One on the toes, heel, or top of the foot suggests arterial problems. A wound on the sole of the foot surrounded by callus is characteristic of diabetic neuropathy. A rapidly expanding ulcer with purple, overhanging edges doesn’t fit typical vascular patterns and needs prompt evaluation.
The wound base tells its own story. A shallow wound with yellowish slough on a background of brown-stained, swollen skin is a classic venous ulcer. A deep, punched-out wound with a pale or black base on a hairless, shiny leg signals arterial disease. Healthy healing tissue is pink and slightly bumpy in texture. Black, dry tissue or cream-colored slough means dead tissue is present and healing has stalled.
Many people have more than one contributing factor. Someone with both diabetes and poor circulation can develop ulcers with mixed features, making the picture less clear-cut. The overall pattern of skin changes, the ulcer’s location, and how it feels (painful versus painless) together paint the most reliable picture of what’s going on.