Venous Ulcers - Symptoms, Causes & Treatment
By ScanSkinAI Editorial Team✓ Reviewed for medical safetyLast updated June 2026
Open sores on the legs that occur when veins don't efficiently return blood to the heart. They're the most common type of leg ulcer.
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Quick Answer
Venous ulcers are shallow, chronic open sores that typically form on the lower legs or inner ankles. They happen when damaged veins struggle to return blood to the heart, causing fluid to pool and pressure to build up. You might notice swelling, weeping, and brown skin discolouration around the wound. Proper medical care is essential because these ulcers rarely heal on their own. The most crucial treatment is compression therapy, using special bandages or stockings to improve blood flow, alongside proper wound dressings and leg elevation.
Clinical Context
Venous leg ulcers account for 70-80% of all leg ulcers, affecting approximately 1% of the population at some point. They result from chronic venous hypertension due to incompetent valves or obstruction. Elevated venous pressure causes capillary damage, tissue hypoxia, and ulceration - typically in the 'gaiter area' (lower medial leg above the ankle). Ulcers are often recurrent; 50% of patients have ulcers lasting over 1 year, and 20% lasting over 5 years. Healing requires compression therapy to reduce venous hypertension. Without addressing the underlying venous insufficiency, recurrence rates exceed 70%.
Symptoms
- Open wound usually on inner ankle
- Irregular shape
- Shallow with uneven edges
- Surrounding brown discoloration
- Leg swelling
- Weeping and crusting
Severity & Progression
Causes & Risk Factors
- Chronic venous insufficiency
- Previous DVT
- Varicose veins
- Obesity
- History of leg injury
Treatment & Management
Compression therapy is the cornerstone of treatment - without it, ulcers rarely heal. Multi-layer compression bandaging or stockings delivering 30-40 mmHg are used. Wound dressings should maintain moist wound environment; options include hydrocolloids, foams, and alginates depending on exudate levels. Debridement removes dead tissue. Treating underlying venous disease (ablation, sclerotherapy, surgery) reduces recurrence. Pentoxifylline (400mg three times daily) can speed healing. Skin grafting or biologics help refractory ulcers. Elevation, exercise, and weight loss complement treatment. After healing, lifelong compression prevents recurrence.
- Compression therapy (most important)
- Wound dressings
- Leg elevation
- Treating venous disease
- Surgery for underlying venous problems
- Skin grafting for large ulcers
Red Flags & Complications
Seek medical attention if you experience any of the following:
- Infection (cellulitis, osteomyelitis)
- Chronic pain significantly impacting quality of life
- Limited mobility
- Social isolation and depression
- Rarely, malignant transformation in longstanding ulcers (Marjolin's ulcer)
- High recurrence rate (70%+ without ongoing compression)
Self-Care Tips
- Wear compression stockings or bandages consistently as prescribed
- Elevate legs above heart level when sitting or lying down
- Walk regularly to activate calf muscle pump
- Keep wound clean and dry between dressing changes
- Maintain healthy weight
- Don't scratch or pick at wound or surrounding skin
- Moisturize surrounding skin to prevent cracking
- Attend all wound care appointments
When to See a Doctor
If you develop a wound on your leg that doesn't heal, especially with leg swelling
Frequently Asked Questions
How did I get this sore on my ankle?
Venous ulcers occur when the valves in your leg veins become damaged or weak. Instead of flowing smoothly back to your heart, blood pools in your lower legs. This increased pressure damages small blood vessels and tissue, eventually breaking down the skin to form an open, shallow wound, often just above the inner ankle.
When should I see a doctor about a leg wound?
You should see a healthcare provider if you have any leg wound that hasn't started to heal within two weeks, or if it is increasing in size. Seek immediate help if you notice signs of infection, such as increased pain, spreading redness, warmth, fever, or a foul-smelling discharge. Early medical intervention prevents dangerous complications like severe tissue infections.
Why does my doctor want me to wear tight bandages over the ulcer?
Medical compression therapy is the absolute most important treatment for venous ulcers. Without firm, consistent pressure from specialised bandages or stockings, the underlying fluid buildup will persist, and the wound will rarely heal. The compression helps your veins push blood back up toward your heart, reducing swelling and giving the skin the environment it needs to repair itself.
How long will it take for my leg ulcer to close up?
Healing time varies greatly depending on the size of the ulcer and your general health, but it is typically a gradual process. Small, superficial ulcers often heal in three to six months with diligent compression and wound care. Larger or deeper wounds can take six to twelve months, and some may require surgical intervention or skin grafting to fully close.
What is the difference between venous and arterial ulcers?
Venous ulcers happen when blood has trouble travelling back up to the heart, causing pooling and swelling, usually on the inner leg. Arterial ulcers happen when blocked arteries prevent oxygen-rich blood from reaching the foot or toes in the first place. Arterial ulcers are often deeper, look punched out, and are much more painful, especially when resting in bed.
Will the ulcer come back after it finally heals?
There is a very high recurrence rate for venous ulcers—over 70% if the underlying circulation issue isn't managed. Because the underlying vein damage remains, you must continue lifelong preventive habits. Wearing properly fitted compression stockings every day, elevating your legs when resting, and staying physically active are critical steps to keep the skin healthy and prevent new sores from forming.
Can I just let my leg ulcer dry out in the air to scab over?
No, letting a chronic ulcer simply dry out is a common myth that can actually delay healing. Venous ulcers require a carefully balanced, moist wound environment to heal properly. Your healthcare provider or wound nurse will apply specific dressings, such as hydrocolloids or foams, which absorb excess weeping fluid while keeping the actual wound bed appropriately moist and protected from infection.
How can ScanSkinAI help with venous ulcers?
ScanSkinAI acts as an early screening aid to help you log and track the appearance of leg wounds and surrounding skin changes. However, it cannot replace a medical evaluation, and it does not provide an official diagnosis. Because venous ulcers require specific medical therapies like prescription compression and advanced wound dressings, you should always have a healthcare professional assess any non-healing sores.
Related Conditions
Medical References
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Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. The content on this page should not be used to diagnose or treat any health problem. Always consult with a qualified healthcare professional for proper medical evaluation, diagnosis, and treatment of your condition.