Swollen ankles are caused by an abnormal build-up or fluid retention between the body's cells. The swelling can progress slowly, over time, before it is noticeable. Then the swelling will first occur in the morning and continue to worsen as the day progresses. People with long-term oedema experience pitting in the swollen ankles, meaning if you were to press the swollen ankle you could see an indentation. Swollen ankles are also known as peripheral oedema.
Age and being overweight are common causes. According to Medline Plus, swelling of the ankles, feet and legs are common problems in older individuals. Prolonged standing in one place or prolonged sitting, such as during automobile trips and aeroplane flights, can cause your ankles to swell. For women, swelling in the ankles can be symptoms of pregnancy or menstrual periods.
Healthy adults should have a daily sodium intake of 2,400 mg or lower. The kidneys regulate the amount of sodium or salt the body excretes and retains. However, if there is too much salt in the body, the kidneys can't excrete it. So the excess sodium begins to accumulate in the body and seep into the surrounding tissues. Since the excess sodium pulls and holds water, both settle in the ankles.
Diseases which affect the entire body can affect the ankles. This occurs when excess, abnormal fluid settles not only in the ankles but also in the legs and feet. For instance, arthritis, which can affect all the joints in the body, can target the joints in the ankles. Gout, another arthritic disease, can also attack the ankles. Gout attacks can last a few days or weeks. In addition, heart disease, liver and kidney failure can create fluid build-up that can settle in the ankles.
In the legs there are small valves within the veins. When these valves weaken, a problem called venous insufficiency can occur. With venous insufficiency, the veins have extreme trouble pumping the blood back to the heart. So along with oedema in the ankles, varicose veins can occur. Varicose veins are once-normal veins under the skin's surface which become damaged and filled with blood and fluid.
Severe chronic conditions, such as lung diseases, can cause an increase in pressure in the blood vessels. These vessels lead from the heart to the lungs. Problems in the lungs puts more pressure on the heart. Thus, the extreme amount of pressure causes oedema in the ankles, legs and feet.