What should you know about swollen lower legs, ankles and feet?

Swollen lower legs, ankles and feet can result from fluid buildup, prolonged sitting or standing, vein problems, medicines, or an underlying health condition; sudden or severe swelling needs prompt assessment. The clinical term for fluid-related swelling is oedema. It may affect one side or both sides, and the skin can feel tight or leave a temporary indentation after pressure. The pattern, timing and accompanying symptoms help a clinician identify the next step.

Swelling after a long journey, desk-based day or period of standing may improve when the legs are raised and movement returns. Veins that do not move blood back towards the heart efficiently can cause heaviness, aching, itching or swelling that becomes more noticeable later in the day; this can occur with Varicose Veins. A sprain, skin infection or other local problem may cause swelling on one side with pain, warmth, redness or tenderness.

Swelling in both legs can also occur when the body retains salt and water or when circulation is affected. Heart Failure can present with ankle or leg swelling, especially alongside breathlessness or reduced exercise tolerance. Chronic Kidney Disease can be associated with fluid retention. Obesity can increase pressure on the veins and make leg swelling more likely, but swelling has several possible explanations and cannot identify its cause by itself.

If the swelling is mild and you otherwise feel well, avoid staying still for long periods. Take regular walking or ankle-movement breaks, raise your legs when resting, and avoid tight socks or footwear that leaves deep marks. Keep the skin clean and moisturised, and check it for cracks, blisters or colour changes. Do not start water tablets, compression garments or a restrictive diet without advice, particularly if you have heart, kidney or circulation problems.

Arrange a medical review if swelling persists, keeps returning, affects daily activities, or follows a new medicine. A clinician may examine the legs, review your medicines and health history, and decide whether blood tests or other checks are appropriate. Note whether one or both legs are affected, when swelling is worst, and whether it changes after elevation.

Seek urgent medical help for sudden swelling in one leg, particularly when it is painful, warm, red or tender. Get emergency help for swelling with chest pain, severe or new breathlessness, fainting, confusion, or coughing blood. These symptoms can signal a problem that needs rapid assessment.

Contact a clinician promptly if the swelling is rapidly worsening, the skin becomes hot or very red, you develop a fever, or a foot becomes unusually cold, pale or numb. People who are pregnant, recently had surgery or prolonged immobility, or have known heart or kidney disease should seek advice sooner when new swelling appears.

You could ask: What are the likely causes of my swelling? Could any of my medicines contribute? Do I need tests? Would leg elevation, exercise or compression be suitable for me? Which changes should prompt urgent help? Bring a list of medicines and a short record of when the swelling appears, what makes it better or worse, and any related symptoms.