Causes - Venous leg ulcer

A venous leg ulcer can develop after a minor injury. It can happen if there's a problem with the circulation of blood in the veins in your leg.

If this happens, the pressure inside the veins increases. This constant high pressure can damage the tiny blood vessels in your skin and make it fragile. As a result, your skin can break and form an ulcer after a knock or scratch.

Risks of developing a venous leg ulcer

A number of factors can increase your risk of developing a venous leg ulcer, including:

  • varicose veins – swollen and enlarged veins caused by malfunctioning valves in the veins
  • previous deep vein thrombosis (DVT) – blood clots that develop in the leg can damage valves in the vein
  • previous injury to the leg, such as a broken or fractured bone which may cause DVT or impaired walking
  • obesity or being overweight – this increases pressure in the leg veins
  • increasing age – people find it harder to move around as they get older


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 23 March 2021
Next review due: 23 March 2024

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