Leg swelling above the knee: what to know

Swelling may affect one leg or both. A recent knock, muscle strain, joint irritation, or skin infection can cause local swelling. If both legs feel heavy or the swelling is worse after standing, [Varicose Veins](/conditions/varicose-veins/) may be relevant because leg veins can allow fluid to collect in nearby tissues. General fluid retention can also occur with [Heart Failure](/conditions/heart-failure/) or [Chronic Kidney Disease](/conditions/chronic-kidney-disease/), especially when ankle swelling or breathlessness occurs too. A larger body size can increase pressure on leg veins; [Obesity](/conditions/obesity/) is one possible contributor, not a diagnosis.

Compare both legs and note when the swelling started, whether it changes during the day, and whether the skin is warm, red, tender, or shiny. Avoid tight clothing around the thigh. Gentle movement and changing position can help circulation, while raising the leg when resting may ease dependent swelling. Do not massage a suddenly swollen, painful leg or start compression garments until a clinician has checked the cause. Arrange a medical review for persistent, unexplained, or recurring swelling; take a list of medicines and any recent injury or long journey.

Seek urgent care for sudden one-sided swelling with pain, warmth, redness, or marked tenderness, particularly after surgery, prolonged immobility, or childbirth. Get emergency help if swelling is accompanied by chest pain, sudden breathlessness, fainting, or coughing blood. Prompt assessment is also needed for fever, rapidly spreading redness, severe pain, numbness, or a pale or cold foot.

Ask whether the swelling appears to be from the veins, soft tissues, a joint, or general fluid retention; whether you need an ultrasound or blood tests; and which activity, elevation, or compression advice is suitable for you.