One swollen leg: when is it urgent?

Swelling in both ankles is common. Swelling, warmth and pain in one leg needs a same-day check.

Mild swelling in both ankles at the end of a hot day or a long flight usually settles overnight. Swelling in one leg is different, especially when the calf is also warm, tender or a different colour. These can be signs of a deep vein thrombosis (DVT), a clot in a deep leg vein.

A DVT is diagnosed with a painless Doppler ultrasound. When it is found early, blood-thinning treatment works well and lowers the risk of the clot moving or causing long-term leg problems.

Call the clinic the same day if one leg suddenly becomes swollen and painful. Go to emergency care straight away if you also feel short of breath, have chest pain or cough up blood.