Why do ankles swell in heat?

Swelling of the ankles is due to an abnormal build-up of fluids. This type of swelling is known as peripheral oedema. There are several reasons why your ankles seem to swell mostly when it is hot outside. It is best to consult a doctor if your ankles are swelling, to rule out any other medical conditions.

Standing Too Long

Summer months mean being outside for longer periods of time. People have a tendency to go more places and do more things in the summer months. You may also be on your feet for longer periods of time, and swelling occurs in the ankles when you stand in one spot for a long time without moving.


People tend to eat more salty foods in the summer months. Grilling outdoors is a popular pastime that many indulge in when it gets warm out. Salt is added to the meat, and more salt is added by the condiments and side dishes. Most people do not realise how much salt they are actually consuming. Large amounts of salt intake cause water retention, which leads to swollen ankles.


Swelling of the ankles when you become overheated is known as heat oedema. This condition occurs when your body cannot get rid of salt and water. Your body is retaining the fluids instead of releasing them.

Blood Vessel Expansion

When it is hot out, your blood vessels expand. When the vessels expand, they can allow fluids to leak into surrounding tissues. Gravity pulls the fluids to your lower extremities and causes swelling.


It is easy to avoid heat oedema. Move around if you find you have been sitting or standing for prolonged periods of time. Exercise such as walking can greatly reduce or eliminate this type of swelling. Limit your salt intake. Too much salt will cause your body to try to dilute it, and the overproduction of fluids causes oedema. Try to keep as cool as possible.