A vascular ulcer is an open wound on the leg or foot that develops because of poor blood circulation. These ulcers don’t heal on their own the way a normal cut would, because the underlying blood flow problem keeps the tissue from getting what it needs to repair itself. They fall into two main categories based on which part of the circulatory system is failing: venous ulcers (caused by poor blood return to the heart) and arterial ulcers (caused by poor blood delivery from the heart). The two types look different, feel different, and require different treatment approaches.
Venous Ulcers vs. Arterial Ulcers
Venous ulcers account for the majority of vascular leg ulcers. They form when the valves inside your leg veins stop working properly, allowing blood to pool in the lower legs instead of flowing back up toward the heart. This pooling, called venous insufficiency, creates sustained high pressure in the veins that gradually damages the surrounding skin and tissue.
Arterial ulcers develop from the opposite problem. Narrowed or blocked arteries, usually from peripheral artery disease, reduce blood flow to the feet and lower legs. Without enough oxygen-rich blood reaching the tissue, the skin breaks down and an ulcer forms. These ulcers tend to be smaller but more painful than venous ulcers, and they carry a higher risk of serious complications because the tissue is already starved for oxygen.
Some people have both venous and arterial problems at the same time, which makes treatment more complex. Distinguishing between the two types is one of the first things a clinician will do, because treating one type with the wrong approach can make the other worse.
Where They Appear and What They Look Like
Venous ulcers almost always form on the inner side of the ankle or the lower calf. They tend to be shallow with irregular edges and a red, weepy wound bed. The surrounding skin often shows its own set of changes: the area may look brownish or darkened from iron deposits leaking out of damaged veins, the skin can feel thick and hardened (a condition called lipodermatosclerosis), and the lower leg may appear swollen. Some people develop a bumpy, cobblestone texture on the skin before an ulcer even opens. These skin changes are signs that venous pressure has been building for a long time.
Arterial ulcers look noticeably different. They typically appear on the toes, heels, or bony areas of the foot. The wound has a distinctive “punched out” appearance with sharp, well-defined edges and a pale or yellowish base that may contain dead tissue. The surrounding skin often looks shiny and hairless, and the foot may feel cool to the touch. Unlike venous ulcers, there’s usually no swelling.
How Pain Differs Between Types
Pain is one of the most useful clues for telling these ulcers apart. Venous ulcers tend to ache with a heavy, dull sensation that worsens when you’ve been standing or sitting with your legs down for long periods. Elevating your legs usually brings relief, because it helps blood drain back toward the heart.
Arterial ulcers cause a sharper, more constant pain. The pain often worsens when you elevate your legs, because gravity is no longer helping push blood down to the feet. Many people with arterial ulcers find they get relief by dangling their feet over the side of the bed, and some end up sleeping in a chair because lying flat makes the pain worse. The ulcer itself is typically painful even without any signs of infection.
What Causes the Tissue to Break Down
In venous ulcers, the persistent high pressure inside damaged veins triggers a chain of events in the skin. The elevated pressure causes white blood cells to migrate out of the blood vessels and into the surrounding tissue, where they release inflammatory chemicals. Over time, this chronic inflammation changes the behavior of the cells responsible for building and maintaining skin. Fibroblasts, the cells that normally produce the structural framework of skin, shift into a state where they contract tissue rather than repair it. Meanwhile, iron from leaking red blood cells accumulates in the tissue and locks immune cells into a destructive mode, breaking down skin rather than rebuilding it. This is why venous ulcers can persist for months or years without healing.
In arterial ulcers, the mechanism is more straightforward. Plaque buildup narrows the arteries feeding the legs, reducing blood flow to the point where the tissue can’t sustain itself. Even minor injuries, like a blister from a tight shoe, can become ulcers because there isn’t enough blood supply to fuel the healing process. As the disease progresses, the pain and tissue damage move from the extremities (toes, foot) upward toward the ankle and calf.
Who Is Most at Risk
Vascular ulcers become significantly more common with age. Prevalence rises steadily in older adults, and among people aged 65 to 95, roughly 1.7% have a venous leg ulcer in any given year. Several factors increase your chances of developing one:
- History of blood clots in the legs, which damage vein valves and lead to long-term venous insufficiency
- Obesity, which increases pressure on leg veins
- Smoking, which accelerates artery damage and is a major driver of peripheral artery disease
- Diabetes, which harms both small and large blood vessels throughout the body
- Prolonged standing or sitting, particularly in jobs that keep you on your feet all day
- Previous leg ulcers, since recurrence rates are high even after successful healing
High blood pressure, high cholesterol, and a sedentary lifestyle further contribute to arterial disease specifically. Many people with vascular ulcers have more than one of these risk factors working together.
How Vascular Ulcers Are Diagnosed
Beyond a visual inspection, one of the most important tests is the ankle-brachial index, or ABI. This quick, painless test compares blood pressure in your ankle to blood pressure in your arm. The result tells your provider whether arterial disease is contributing to the ulcer, which directly affects treatment decisions.
A normal ABI falls between 1.0 and 1.3. An ABI of 0.9 or lower indicates peripheral artery disease: 0.7 to 0.9 suggests mild disease, 0.4 to 0.7 is moderate, and below 0.4 is severe. An unusually high reading above 1.4 can mean the arteries have become stiff and calcified, which is common in older adults and people with diabetes.
This number matters because the main treatment for venous ulcers, compression therapy, can be dangerous if significant arterial disease is present. Compressing a leg that isn’t getting enough blood flow in the first place can worsen the problem. The ABI helps determine whether compression is safe and at what pressure level.
Treatment for Venous Ulcers
Compression therapy is the cornerstone of venous ulcer treatment. Wrapping the lower leg with specialized bandages applies steady pressure that counteracts the pooling of blood, improves vein function, and reduces the swelling and inflammation that prevent healing. For active ulcers, a sustained pressure of 30 to 40 mmHg at the ankle is the standard recommendation, supported by strong evidence. During walking, interface pressures exceeding 50 to 60 mmHg further improve the vein’s pumping ability.
For people who also have mild arterial disease (with an ABI between 0.6 and 0.8), modified compression using stiffer materials at lower pressures, under close monitoring, can still improve both arterial and venous circulation. Below an ABI of 0.6, compression generally isn’t safe.
Wound care is the other essential piece. Vascular ulcers heal best in a moist environment, so dressings are chosen to keep the wound bed hydrated without becoming waterlogged. No single type of dressing has proven superior to others. The choice depends on the wound’s characteristics: how much fluid it’s producing, whether dead tissue needs to be removed, and how deep it is.
Removing dead tissue from the wound, called debridement, helps convert a stalled chronic wound into one that can proceed through normal healing stages. This can be done mechanically by a skilled clinician, through special dressings that soften and lift dead tissue over time, or even with medical-grade fly larvae that selectively digest dead tissue while leaving healthy tissue intact.
Treatment for Arterial Ulcers
Because arterial ulcers stem from blocked or narrowed arteries, treatment focuses on restoring blood flow. This often means a procedure to open or bypass the affected artery. Without improved circulation, the ulcer simply won’t have the blood supply it needs to heal, regardless of how well the wound itself is managed.
Wound care for arterial ulcers follows similar principles of keeping the wound clean and moist, but compression is avoided. Managing cardiovascular risk factors, including blood pressure, cholesterol, blood sugar, and smoking, is critical both for healing and for preventing the arterial disease from worsening elsewhere in the body.
What Happens if an Ulcer Doesn’t Heal
Vascular ulcers that remain open for extended periods carry real risks. Infection is the most immediate concern. Bacteria can colonize the wound bed and spread into surrounding soft tissue, causing cellulitis. In severe cases, infection can reach the bone underneath the ulcer, a condition called osteomyelitis that is much harder to treat and may require prolonged therapy or surgery.
Chronic wounds that persist for years also carry a small but documented risk of malignant changes, where the cells at the ulcer’s edge transform into skin cancer. This is uncommon but is another reason that non-healing ulcers need ongoing professional evaluation rather than passive home care. Vascular ulcers are notoriously slow to heal, with some taking six months to a year or longer, and recurrence after healing is common. Continued use of compression stockings and attention to the underlying circulation problems are what give you the best chance of keeping them from coming back.