A leg ulcer is a long-lasting (chronic) sore that takes more than 2 weeks to heal. They usually develop on the inside of the leg, just above the ankle.
The symptoms of a venous leg ulcer include pain, itching and swelling in the affected leg.
There may also be discoloured or hardened skin around the ulcer, and the sore may produce a foul-smelling discharge.
See your GP if you think you have a leg ulcer, as it'll need specialist treatment to help it heal.
Your GP will examine your leg and may carry out additional tests to rule out other conditions.
A venous leg ulcer is the most common type of leg ulcer, accounting for more than 90% of all cases.
Venous leg ulcers can develop after a minor injury, where persistently high pressure in the veins of the legs has damaged the skin.
Venous leg ulcers are estimated to affect around 1 in 500 people in the UK, although they become much more common with age.
It's estimated around 1 in 50 people over the age of 80 has one.
You're more at risk of developing one if you previously had deep vein thrombosis (DVT) or find it difficult to walk because of a problem such as:
People with swollen and enlarged veins (varicose veins) also have a higher risk of developing venous leg ulcers.
Most venous leg ulcers heal within 3 to 4 months if they're treated by a healthcare professional trained in compression therapy for leg ulcers.
But some ulcers may take longer to heal, and a very small number never heal.
Treatment usually involves:
Antibiotics may also be used if the ulcer becomes infected, but they do not help ulcers heal.
But unless the underlying cause of the ulcer is addressed, there's a high risk of a venous leg ulcer coming back after treatment.
Underlying causes could include immobility, obesity, previous DVT or varicose veins.
There are several ways to help prevent developing a venous leg ulcer in people at risk.
These measures are particularly important if you previously had a leg ulcer.
This is because you're at increased risk of having another one in the same leg within months or years.
Other common types of leg ulcer include:
Most ulcers caused by artery disease or diabetes occur on the foot rather than the leg.