Wound that won't heal

What is a wound that won't heal, and how common is it?

A wound that won't heal (a chronic or hard-to-heal wound) doesn't move through the normal stages of healing in a timely way, and often gets stuck in the swelling (inflammatory) stage¹. Several things usually overlap, such as an underlying illness, poor nutrition and pressure on the area¹.

There's no single agreed cut-off for when a wound counts as stalled. One guide is a wound that hasn't healed or shrunk by about 40–50% within 4 weeks². A leg ulcer (an open sore between the knee and ankle) is long-lasting when it takes more than 2 weeks to heal³.

These wounds are common in some groups. Venous leg ulcers often affect older adults and can last a long time⁴, and as many as 34% of people with diabetes develop an ulcer on the sole of the foot over their lifetime⁵.

What can cause a wound not to heal?

Most leg ulcers come from vein problems. About 80% are venous ulcers, about 15% are arterial (from poor blood flow in the arteries), and about 5% have other causes, such as injury, inflammatory conditions or a skin tumour⁶³. Venous ulcers usually develop on the inside of the leg between the knee and ankle³.

In people with diabetes, long-term high blood sugar can damage nerves and blood vessels and keep inflammation going, which slows healing of foot ulcers⁷. Ongoing pressure on one area can also stop a wound healing¹.

How is the cause found?

A podiatrist or doctor looks at the whole person, not just the wound. They ask about your health history and examine your legs and the wound for signs of vein disease, artery disease or other causes⁶.

Your circulation is checked too, usually with a Doppler ABPI (a test that compares blood pressure at your ankle and arm using a small ultrasound probe), before any compression⁶. Feeling foot pulses alone can't reliably rule out poor circulation in people with diabetes⁸. Automated devices can underestimate artery disease in people with leg ulcers⁹, and a reading can look falsely normal in people with diabetes or kidney disease because of stiff, calcified arteries¹⁰. So results are read alongside the examination⁶.

For a new diabetic foot ulcer, a probe-to-bone test (a gentle check with a thin probe for whether the wound reaches bone) and X-rays are recommended, with an MRI scan if a deep infection or abscess is suspected¹¹.

What helps first?

Treatment depends on the cause.

• Venous leg ulcers: compression (firm bandages or stockings that support the veins) is the first treatment¹²⁶. It's used only after circulation is checked, because compression isn't suitable if you have peripheral artery disease (narrowed leg arteries)⁹.
• Diabetic foot ulcers: care usually combines taking pressure off the area, blood sugar control, treating infection, removing dead tissue and modern dressings⁷.
• Advanced arterial ulcers: restoring blood flow with a procedure or surgery is the first treatment, aiming to reduce pain and save the leg¹².

Eating enough calories, protein, vitamins A and C and zinc supports healing, and unmet energy and protein needs can delay it¹.

What helps if that isn't enough?

If a wound hasn't healed or shrunk by about 40–50% after 4 weeks, referral to a qualified wound care provider for a closer look is advised². It's worth checking whether infection, pressure, poor circulation, nutrition or blood sugar is holding healing back. If poor blood flow is the problem, a procedure to restore it may be needed rather than more local treatment¹².

For diabetic foot ulcers, extra options such as negative pressure wound therapy (a dressing that applies gentle suction) and hyperbaric oxygen therapy (breathing oxygen in a pressurised chamber) aren't cure-alls. They belong within a team plan that includes blood sugar control, infection care and taking pressure off the foot¹³.

Will it heal, and how can I stop it coming back?

Outlook depends on the type of wound, and ulcers often come back. After a diabetic foot ulcer closes, the risk of a new one is highest straight away: 40% have another within 12 months, and nearly 60% within 3 years⁵. It helps to arrange close early follow-up, check your feet regularly and report any new sore early.

After a venous leg ulcer heals, compression stockings are a safe and effective way to help stop it returning⁴. Circulation should still be checked first, and poor blood flow to the limb or fluid in the lungs means compression isn't suitable⁴⁹.