Introduction
In the case of a unilateral swollen ankle, swelling occurs only on one foot. This can be on the inner or outer ankle, although the latter is more common. Often there is also an additional swelling in the surrounding area, such as the foot or lower leg.
There are several possible causes for a unilateral swollen ankle. The swelling is usually caused by an accumulation of fluid. This occurs, for example, when the veins are diseased. Less frequently, the swelling can also be caused by an accumulation of fatty tissue.
Causes
There are several causes for a unilateral swollen ankle. For example, it can be swelling due to an allergic reaction or inflammation of the tendons. A disease of the veins with a disturbance of the blood transport can also be a possible cause.
An accumulation of lymph, known as lymphedema, can also occur in the event of an infection, for example. In a trauma, i.e. an injury caused by an accident, among other things, a one-sided swelling on the ankle often occurs together with other symptoms such as wounds or a fracture. After an accident or a fall, for example, bending over in high shoes, a one-sided swollen ankle is common.
The swelling is part of the body’s natural reaction to the injury. It occurs as part of a so-called inflammatory reaction and is an expression of the activated immune system. The swelling can also be a hematoma, i.e. a bruise.
This is caused by an injury to small blood vessels in the area of the ankle. This causes bleeding at this point and the body needs time to remove the blood. After an insect bite on the ankle, for example a wasp sting, there is also a one-sided swelling.
This generally occurs as part of the inflammatory reaction. This means that the body’s immune system is activated by the insect’s venom and reacts with swelling, redness and warming. However, it is important to pay attention to the size of the swelling and the speed at which the swelling increases.
In some cases, this can be an allergic reaction to the insect venom. This usually occurs with symptoms such as dizziness, rash or shortness of breath and should be treated by a doctor as soon as possible. Inflammation of the tendons, also known as tendinitis, can also lead to a swollen ankle on one side.
An inflammation of the so-called peroneal tendon is particularly typical in this case, as it runs along the outer ankle in this area. It belongs to the short and long fibula muscles and can be inflamed by overloading. Inflammation of the tendon also manifests itself by the occurrence of pain when the muscles are strained.
It is caused, for example, by prolonged overweight, as the fibula muscles are then subjected to increased strain when running. Repeated bending over, for example when running with high shoes, can also lead to inflammation of the peroneal tendon. This topic may also be of interest to you:
- Foot folded outwards
A unilateral swollen ankle can sometimes also be caused by thrombosis.
This can be caused by a disease of the veins as well as by a disease of the arteries, the former being more common. This is also known as deep vein thrombosis and is typically accompanied by pain when applying pressure to the area, overheating and redness. Swelling is not a typical symptom of the much rarer arterial thromboembolism, which is a vascular occlusion caused by a clot.
It is more likely to be accompanied by paleness and severe pain, but must be treated as soon as possible. Varicose veins are caused by a disease of the veins and often lead to one-sided swelling, for example also in the area of the ankle. This leads to a disturbance in blood transport, which causes superficial veins to dilate and become visible as varicose veins.
If nothing is done about this, the varicose veins will eventually no longer be able to transport the blood that continues to back up. This also overloads the lymphatic system and leads to an accumulation of fluid, also called oedema. To prevent this, a vascular doctor (angiologist, phlebologist) should be consulted at an early stage.
Gout causes an excessive increase of uric acid in the blood, which is usually caused by damage to the kidneys.This leads to an inflammation of various joints, including the ankle joint of the foot. This inflammation is accompanied by typical signs, including swelling. This is intensified by the accumulation of many substances and cells important for the inflammation. In addition, there is severe pain, which often occurs at rest, i.e. without movement. Therefore, gout should be treated by a doctor as early as possible.
