A varicose ulcer, more commonly called a venous leg ulcer, is an open wound on the lower leg caused by chronically poor blood flow in the veins. These ulcers typically develop near the ankle, especially on the inner side, and can take weeks or months to heal. They affect roughly 1.1% of all adults and represent the most advanced stage of chronic venous disease.
How Varicose Ulcers Form
Healthy leg veins have one-way valves that push blood upward toward the heart. When those valves weaken or fail, blood pools in the lower legs, creating sustained high pressure in the veins. This pressure backs up into the smallest blood vessels near the skin, slowing blood flow to a crawl.
That sluggish flow traps white blood cells in the tiny capillaries. The trapped cells release enzymes and inflammatory molecules that damage the capillary walls, allowing proteins from the blood to leak into surrounding tissue. Those proteins form a fibrous barrier around the capillaries that acts like a cuff, blocking oxygen from reaching the skin. Starved of oxygen, the tissue becomes inflamed, breaks down, and eventually opens into a wound that won’t heal on its own.
This process doesn’t happen overnight. Most people progress through earlier stages of venous disease first: visible varicose veins, leg swelling, skin discoloration or a brownish staining around the ankles, and a hardening of the skin called lipodermatosclerosis. An ulcer is the final stage, classified as C6 in the international staging system doctors use for chronic venous disease.
What a Varicose Ulcer Looks Like
Varicose ulcers have a distinctive appearance. They usually sit on the inner ankle or lower calf, have irregular borders, and a moist, weeping base with reddish granulation tissue. The surrounding skin is often discolored, swollen, and may feel warm or itchy. Some people notice a dull ache that gets worse when the leg hangs down and improves with elevation.
Pain varies. Some varicose ulcers cause only mild discomfort, while others are genuinely painful, particularly when infected or if the wound is large. The ulcers can range from a small coin-sized spot to wounds that wrap around a significant portion of the lower leg.
Varicose Ulcers vs. Arterial Ulcers
Not all leg ulcers come from vein problems. Arterial ulcers result from poor arterial blood supply and look and behave quite differently. Knowing the difference matters because the treatment approach is nearly opposite.
- Location: Varicose ulcers favor the inner ankle. Arterial ulcers tend to appear on toes, heels, bony prominences, and the outer ankle or front of the shin.
- Appearance: Varicose ulcers have irregular edges and a moist, reddish base. Arterial ulcers look “punched out” with sharp borders and a pale, white, or dark base.
- Pain pattern: Varicose ulcers hurt more when the leg is dangling and feel better when elevated. Arterial ulcers do the opposite, worsening at night when the legs are up in bed.
- Pulses: Foot pulses are typically normal with varicose ulcers. With arterial ulcers, pulses are weak or absent.
Some people have “mixed” ulcers involving both venous and arterial disease. Before starting any treatment, a simple test called the ankle-brachial index (ABI) compares blood pressure at the ankle to blood pressure in the arm. A result between 0.8 and 1.3 confirms adequate arterial flow and makes compression therapy safe. Below 0.8, arterial disease needs to be addressed first.
Compression Therapy: The Core Treatment
Compression is the foundation of varicose ulcer treatment. Multi-layer bandages or compression stockings apply graduated pressure to the leg, counteracting the venous pooling that caused the ulcer in the first place. The standard therapeutic range is 30 to 40 mmHg of pressure at the ankle, which is enough to support venous return without cutting off arterial flow in people with a normal ABI.
Compression works by squeezing the veins to improve blood flow back toward the heart, reducing swelling, and helping oxygen reach the damaged tissue. It isn’t comfortable at first, and the bandages need to be reapplied regularly, often by a nurse or trained clinician. But without it, most varicose ulcers simply will not close.
For people with mixed ulcers where the ABI falls below 0.8, lighter compression under 30 mmHg with short-stretch bandages can be used, but only under specialist supervision to avoid compromising arterial blood supply to the foot.
How Long Healing Takes
Healing time depends heavily on ulcer size. Small ulcers can close in as little as three weeks. Larger ulcers, particularly those over 7 square centimeters, often take two to three months or longer. A systematic review of healing times found that small ulcers healed in an average of about 22 days, while larger ones took a median of 56 to 82 days.
Some ulcers persist for months or even years, especially when compression isn’t used consistently, when infection complicates the wound, or when the underlying vein problem isn’t corrected. Roughly half of all venous ulcers recur after healing, which is why addressing the root cause matters as much as wound care.
Procedures to Prevent Recurrence
Compression manages symptoms, but fixing the faulty veins reduces the chance the ulcer comes back. Endovenous ablation, a minimally invasive procedure that seals off damaged veins using heat, has become the standard approach. The vein is closed from the inside through a small catheter, usually under local anesthesia, and blood reroutes through healthier veins.
The case for early intervention is strong. In one landmark trial (the ESCHAR study), adding vein surgery to compression therapy cut the four-year recurrence rate from 56% to 31%. That’s a meaningful difference for people who have already endured months of wound care and want to avoid going through it again. Current guidelines from both the Society for Vascular Surgery and the European Society for Vascular Surgery recommend treating the underlying venous reflux rather than relying on compression alone.
Signs of Infection
Open wounds are vulnerable to bacterial infection, and varicose ulcers are no exception. Warning signs include a noticeable increase in wound drainage or a change in its color, worsening pain that seems out of proportion to the wound’s size, spreading redness around the ulcer edges, warmth, foul odor, and systemic symptoms like fever or chills. Delayed healing, where an ulcer that had been improving suddenly stalls or worsens, can also signal infection.
Infection doesn’t just slow healing. If bacteria spread into deeper tissue or the bloodstream, it becomes a serious medical problem. Any combination of the signs above warrants prompt evaluation, especially in people with diabetes or compromised immune function.
Daily Management and Self-Care
Beyond compression and medical procedures, several practical habits support healing and reduce recurrence. Elevating the legs above heart level for 30 minutes several times a day helps drain pooled blood. Regular walking activates the calf muscle pump, which is the body’s natural mechanism for pushing venous blood upward. Prolonged standing or sitting with the legs down does the opposite and should be minimized.
Keeping the surrounding skin moisturized prevents cracking, and avoiding trauma to the lower legs reduces the risk of new wounds. Once an ulcer heals, wearing graduated compression stockings daily is the single most important step to prevent it from returning.