Ankle swollen on one side


If the ankle is swollen on one side, swelling will only occur on one foot. This can be on the inner as well as on the outer ankle, the latter being more common.

Often there is also swelling in the area, such as the foot or the lower leg. There are various possible causes for a one-sided swollen ankle. The swelling is usually caused by a build-up of fluid. This occurs e.g. with a disease of the veins. Much less often, the swelling can also be an accumulation of fatty tissue, for example.


There are various causes of a one-sided swollen ankle. For example, it may be swelling due to an allergic reaction or inflammation of the tendons.

A disease of the veins with a disruption of the blood transport can also be the cause. A build-up of lymph called lymphedema can also occur, for example, with an infection. In the case of trauma, i.e. an injury from an accident, among other things, a one-sided swelling of the ankle often occurs along with other symptoms, such as wounds or a fracture.

Find out all about the topic here: The causes of swollen ankles.

Accident or fall

After an accident or fall, for example twisting your ankle in high heels, the ankle is often swollen on one side.

The swelling is part of the body's natural response 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 leads to a bleeding at this point and the body needs time to evacuate the blood.

Insect bite

After an insect bite on the ankle, for example a wasp sting, there is also unilateral swelling.

This generally occurs as part of the inflammatory reaction. This means that the body's immune system is activated by the insect's poison and reacts with swelling, reddening and warming. It is important, however, that the size of the swelling and the speed at which the swelling increases are taken into account. In some cases it can also be an allergic reaction to the insecticide. This usually occurs with symptoms such as dizziness, rash or shortness of breath and should be treated by a doctor as soon as possible.


Tendonitis, also called tendinitis, can also lead to a one-sided swollen ankle.

Inflammation of the so-called peroneal tendon is typical for this, as it runs in this area on the outer ankle. It belongs to the short and long fibula muscles and can become inflamed when overworked. Tendonitis is also noticeable when the pain occurs when the muscles are used. She comes e.g. caused by prolonged obesity, as the fibula muscles are then more stressed when running. Repeated twisting, for example when walking in high heels, can also lead to inflammation of the peroneal tendon.

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A one-sided swollen ankle can sometimes be caused by a thrombosis.

This can arise from a disease of the veins as well as a disease of the arteries, the former being more common. This is also known as deep vein thrombosis and typically also manifests itself as pain when pressure is applied to the area, overheating and redness.

In the much rarer arterial thromboembolism, which is a vascular occlusion caused by a clot, swelling is not a typical symptom. It is more associated with pallor and severe pain, but must be treated as soon as possible.

Read more on this topic:

  • Causes of Thrombosis
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Varicose veins

Varicose veins are caused by a disease of the veins and often lead to one-sided swelling, for example in the area of ​​the ankle.

The blood transport is disturbed, as a result of which superficial veins expand and become visible as varicose veins. If nothing is done about this, at some point the varicose veins will no longer be able to transport the blood that is still backing up. This also overloads the lymph system and creates an accumulation of fluid, also known as edema. To prevent this, a vascular doctor (angiologist, phlebologist) should be consulted at an early stage.

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In gout, there is an excessive increase in uric acid in the blood, which is usually caused by damage to the kidney.

This leads to inflammation of various joints, including the ankle joint on the foot. This inflammation is associated with typical signs, including swelling. This is intensified by the accumulation of many substances and cells that are important for inflammation. In addition, there is severe pain, which often occurs at rest, i.e. without movement. Therefore, the gout should be treated by a doctor as early as possible.

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Other accompanying symptoms

A unilateral swollen ankle can have many accompanying symptoms, which vary depending on the cause of the swelling.

The swelling itself can appear suddenly or over a longer period of time and develop at different speeds. The swelling is often a sign of an inflammatory response in the body caused by the activation of the immune system. This also leads to reddening of the area, as well as pain and overheating. Furthermore, the foot is often restricted in its movement due to the swelling.


If a one-sided swollen ankle is accompanied by pain, this is often a sign of an acute cause, such as after a fall or an insect bite.

In the case of pain, attention should be paid to whether it occurs at rest or when the foot is moving. For example, pain in a swollen ankle that occurs at rest can occur with inflammation of the joint, such as in gout. Pain that occurs during movement, on the other hand, is more a sign of acute overloading of the joint or the surrounding area, such as tendonitis.

Painless swelling

If a one-sided swollen ankle occurs without pain, there are various possible causes.

If the swelling mainly occurs in the evening, it may be a late injury to the ankle. If the joint is used during the day, it reacts with swelling in the evening, which can be absolutely painless. However, a painless swelling can also be an indication of a tumor. These are often harmless tumors, such as an accumulation of adipose tissue. This is also known as a lipoma and can be removed in one small, straightforward procedure.


Treatment for a unilateral swollen ankle depends on the underlying cause.

In many cases the swelling can be reduced by cooling the swollen area, e.g. with a cold pack or compress. Then there is usually an inflammatory reaction of the body, for example in the case of an insect bite or a slight sprain. Cooling can also be helpful in the event of an allergic reaction; depending on the type of allergy, so-called antihistamines should also be taken if necessary. Cooling can also help after an accident. However, it should also be clarified whether there is a break, for example.

If the swelling is the result of a disease of the veins, for example if there are varicose veins, elevating the leg helps. This promotes the return flow of blood from the leg. A compression stocking can also be helpful. In the case of other vascular diseases such as thrombosis, a doctor should be consulted and anticoagulation, i.e. therapy to prevent the formation of blood clots, should be carried out.

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Home remedies

There are several home remedies that can help with a one-sided swollen ankle.

In general, it usually makes sense to cool the swelling with the help of an ice pack or a wet cloth. Quark, for example in the form of a quark wrap, can also relieve the swelling. If there is an insect bite, it can also help if an onion is placed on the area of ​​the puncture. Raising the leg with the swollen ankle can also help relieve the swelling, depending on the cause.

Read more on the subject at: Home remedies for swollen ankles


Various homeopathic remedies can help with a one-sided swollen ankle.

These include, for example, arnica or horse chestnut extract. These remedies help against swelling by promoting the removal of fluid that has accumulated in the area of ​​the ankle.

Aloe vera can also be helpful for a one-sided swollen ankle, as it has a decongestant and also has a cooling effect. Camphor can also help with a disturbance in the blood flow that leads to swelling. It also has a pain reliever effect.


The diagnosis of a one-sided swollen ankle includes the anamnesis, i.e. the doctor-patient discussion, and the clinical examination of the ankle. This allows further symptoms to be recorded and possible causes can be concluded. The time of occurrence and the development of the swelling can provide further clues.

Depending on the suspicion or cause, further investigations may be important. This includes, for example, an examination of the blood, an ultrasound of the surrounding vessels or an X-ray image.

Course of disease

The course of the disease of a one-sided swollen ankle depends on the cause.

Often the cause is not serious, such as an insect bite or a minor sprain. Accordingly, it only takes a few hours for the swelling to subside without any further consequences. However, if the swelling on the ankle persists for several days or even enlarges, this may indicate a more complex cause. Accordingly, swellings on the ankle caused by vascular diseases are usually associated with a longer course of the disease.

Duration and forecast

The duration of a unilateral swollen ankle also depends on the underlying cause. For example, if it is a sting or mild inflammation, the swelling will usually go away completely after a few hours.

With vascular diseases or more complex inflammations, the swelling usually lasts for a longer period of time or occurs depending on the time of day. However, preventive measures such as sufficient exercise or compression stockings can be used.

The prognosis is usually good if the causal disease is identified and treated in good time.