Swollen ankles and feet: what causes ankle swelling

Do your shoes feel tight by evening, and does a finger press leave a dent near the ankle bone? Swollen ankles and feet are most often caused by fluid building up in the tissues — this is called edema (oedema). It can be harmless, or it can be the first signal of problems with the heart, veins or kidneys — the difference lies in the details.

Why feet and the area around the ankle bone swell

The mechanism is simple: fluid leaks from the capillaries into the tissues and stays there. The causes fall into three groups — increased pressure in the capillaries, reduced protein in the blood plasma, and increased permeability of the vessel wall. Everyday triggers: standing or sitting in one position for a long time, too much salt, excess weight, pregnancy, hot weather and long walks. Among medications, some blood pressure drugs, contraceptives, hormone therapy, antidepressants and steroids can cause edema. Then come varicose veins, thyroid problems, injuries, insect bites, infections, heart, kidney and liver disease, and blood clots.

Swelling on only one leg: what to watch for

One-sided swelling is a separate matter. With thrombophlebitis, blood outflow is impaired below the clot: the leg is firm, the skin over the area of thrombosis is purplish-red, and palpation is painful. When lymphatic drainage is impaired, the limb is also firm, but the skin is pale. Inflammatory swelling after an injury, burn or infection is reddish and painful. If only one ankle or foot is swollen and you don't understand why, this is a reason for an urgent medical consultation.

When both legs swell: heart, kidneys, veins

Cardiac edema is the most common type of hydrostatic edema: first the feet and lower legs (when you are upright), then the sacrum and lower back (when you are lying down), and in severe cases the whole body and body cavities. Kidney edema is soft, the skin is pale, and the face and the area around the eyes are also involved. In liver cirrhosis, edema of the legs, lower back and abdomen occurs together with ascites. Varicose veins can also cause leg swelling.

How to tell edema from swelling after a bruise

Signs of edema: the skin is taut or shiny, changes color, becomes dry, with discomfort, stiffness and a dent when pressed. Trauma (for example, a sprain) is one of the causes of edema. If the swelling after an injury is large or increasing, you need a doctor.

Which tests help find the cause of edema

The doctor starts with an examination and history: one leg or both, when it appeared, medications, chronic diseases. The doctor determines which tests are needed.

Warning signs that require a doctor

For symmetrical swelling that does not improve within a few days, or if it worsens or you already have known heart, kidney or vein disease, see a doctor.

• One leg swells for no clear reason
• The swelling appeared very suddenly or increased sharply
• The skin in the swollen area is red or hot
• Very high temperature, fever or chills
• Swelling in a person with diabetes

Myth: edema is always "just water." Fact: it can be caused by a clot or heart failure.

On its own it is not a reason to call an ambulance; 103 or 112 — if shortness of breath or difficulty breathing appears, chest pressure or pain, you are coughing up blood, you feel severe palpitations, dizziness, weakness, nausea or clammy sweat. This may be a blood clot in the lungs — immediate help is needed.

This material is for reference: the figures and signs help you get your bearings, but they do not replace a doctor's consultation — if in doubt, see a specialist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer