Leg swelling (oedema) happens when fluid accumulates in the tissues of the lower leg. It can have many causes, so it is important to get a proper assessment rather than assuming it is always a vein issue.

Venous insufficiency — where damaged vein valves allow blood to pool in the lower leg — is one of the most common causes. The increased pressure in the vein pushes fluid out through the vein wall into the surrounding tissue. This is typically worse at the end of the day, after prolonged standing, and in hot weather. Elevating the legs and wearing compression stockings often improves it.

Other causes of leg swelling include lymphoedema (damage to the lymphatic drainage system), heart failure, kidney disease, liver disease, low protein levels, medications (such as some blood pressure drugs and anti-inflammatories), and deep vein thrombosis (DVT) — a blood clot in the deep veins, which requires urgent assessment.

You should seek prompt medical review if your leg swelling is sudden, affects only one leg, is associated with pain, redness, or warmth, or if you have had recent surgery, a long flight, or immobility — these features can indicate DVT and should not be ignored. At our Woolloomooloo vein clinic, in Sydney’s inner east, we can check your swollen legs for any signs of DVT or other venous conditions.