Swollen ankles

Swollen ankles happen when fluid collects in the tissues of the lower legs, a form of oedema. Gravity pulls fluid downward, so the ankles and feet are where it first shows, and pressing the skin often leaves a temporary dent (pitting). Many causes are benign: prolonged standing or sitting, hot weather, being overweight, pregnancy, and certain common medications (some blood pressure drugs, anti-inflammatories, steroids and hormones). Whether one or both legs are affected is an important clue. Swelling of both legs suggests a body-wide (systemic) cause: heart failure, where the heart cannot clear fluid and it backs up into the legs (usually with breathlessness); kidney disease, where the body retains salt and water or loses protein; liver disease, where low protein and fluid shifts cause swelling; and a low blood albumin from any cause, which lets fluid leak from the vessels. Swelling of just one leg is more likely to be local — a deep vein clot (which can be serious, with pain and redness), an infection, or a problem with the leg veins (chronic venous insufficiency) or lymphatic drainage. So the pattern, speed of onset and accompanying symptoms guide how concerning it is.

• Prolonged standing or sitting, heat, or being overweight — common and benign.
• Pregnancy — usual mild swelling, but sudden or marked swelling needs checking.
• Medications — some blood pressure drugs, anti-inflammatories, steroids, hormones.
• Heart failure — swelling of both legs, usually with breathlessness.
• Kidney disease — salt and water retention or protein loss.
• Liver disease or a low blood albumin — fluid leaks from the vessels.
• A deep vein clot, infection or vein problem — usually one leg, sometimes with pain, redness or warmth.

Swollen ankles are assessed clinically first, noting whether one or both legs are involved and any breathlessness. Blood tests help find a systemic cause: NT-proBNP if heart failure is suspected, kidney function (creatinine, eGFR) and a urine test for protein for kidney disease, albumin and liver function for a low protein state or liver disease, and a full blood count and thyroid tests as relevant. If a clot in one leg is suspected, a D-dimer and an ultrasound scan are used. Mediora.AI can surface a heart, kidney or low-albumin pattern from your results that fits the swelling, but the cause depends on the clinical picture — especially one leg versus both, and any breathlessness — and is worked out by your doctor.