There are many different causes of swollen ankles. In most cases, swelling is due to injury or edema.

The term edema means swelling due to the accumulation of excess fluid. It is particularly common in the lower leg, ankles, and feet.

In this article, we look at 11 causes of swollen ankles and cover some of the best treatment options.

Possible causes of swollen ankles include:

1. Foot or ankle injury

Man holding his ankle due to a swollen ankle
A person may experience inflammation due to an injury on the ankle or foot.

People who sustain an injury to the foot or ankle may experience inflammation in that area, causing it to appear swollen.

An ankle sprain is one of the most common foot injuries.

The American Orthopedic Foot and Ankle Society recommend the following home treatment for a sprained ankle:

  • resting
  • wearing an ankle brace
  • applying ice in a thin piece of cloth for no more than 20 minutes
  • applying a compression wrap
  • elevating the foot above the waist

2. Cellulitis

Bacterial infections in the skin are called cellulitis. People with diabetes are particularly prone to this type of infection.

Cellulitis can cause a range of symptoms, including redness, warm skin, and swelling that spreads rapidly. In rare cases, cellulitis can be life-threatening without treatment.

People with cellulitis need to take antibiotics. It is essential to tell a doctor if the swelling does not reduce or gets worse after a few days of treatment.

3. Medication side effect

Some medications can cause the ankles to swell as a side effect. Such medications include:

People who suspect that their ankles are swollen as a side effect of medication may wish to talk to their doctor.

A doctor may prescribe diuretic medications or suggest methods for reducing the swelling if it is uncomfortable.

4. Chronic venous insufficiency

The most common type of edema is from chronic venous insufficiency (CVI). CVI is a condition that affects the valves in the leg veins.

These valves usually make sure that blood flows toward the heart. In CVI, however, the valves malfunction and allow some of the blood to flow backward and pool in the lower legs and ankles.

Although CVI does not have severe complications, it can be painful and uncomfortable. It may also cause noticeable changes to the skin.

A doctor can help a person with CVI develop a personalized treatment plan.

Examples of some treatment options include:

  • keeping the legs raised to improve blood flow
  • wearing compression stockings to reduce swelling
  • taking medications, such as aspirin
  • undergoing radiofrequency ablation, which uses heat to close the affected vein

5. Blood clots

Sometimes, a blood clot, or “thrombosis,” can develop in one of the veins in the arm or leg. This is called deep vein thrombosis (DVT) and requires urgent medical attention.

DVT obstructs the flow of blood returning to the heart, causing it to build up in the affected limb.

Sometimes, the body is able to compensate for the blockage by gradually diverting blood through smaller neighboring veins. Over time, these veins get larger and are able to drain blood from the limb.

If these veins do not increase in size, the limb may remain swollen. Persistent pain and swelling after a DVT is called post-thrombotic syndrome.

People who experience a DVT should consider:

  • elevating the affected limb
  • wearing compression stockings to promote blood flow
  • taking anticoagulant medications, or blood-thinners
  • undergoing a stenting procedure, during which a surgeon inserts a tube called a stent into the vein to keep it open

6. Pregnancy

Pregnant woman with swollen ankles
Swollen ankles are a common side effect of pregnancy.

During pregnancy, the body produces more blood and bodily fluids to support the developing fetus.

Swelling is a common side effect of pregnancy, especially in the third trimester. It can affect the ankles, feet, legs, face, and hands.

Slight swelling is normal and usually harmless. However, sudden swelling of the hands and face could be a sign of a potentially life-threatening condition called preeclampsia.

Women who experience mild swelling during pregnancy may get relief from home remedies such as:

  • eating foods high in potassium
  • reducing salt intake
  • avoiding caffeine
  • wearing comfortable shoes
  • wearing support stockings
  • avoiding standing for long periods
  • elevating the feet when resting
  • applying cold compresses
  • wearing loose-fitting clothes
  • limiting time outdoors during hot weather
  • resting in a pool

7. Preeclampsia

Preeclampsia is a life-threatening condition that can occur during the second or third trimester of pregnancy, or up to 6 weeks after giving birth.

Preeclampsia is characterized by dangerously high blood pressure and protein in the urine. It can cause a variety of symptoms, including headaches, changes in vision, weight gain, and edema.

Preeclampsia that occurs during pregnancy can also affect the fetus.

It requires urgent medical treatment. Treatment may include medications to prevent seizures and lower blood pressure.

Delivering the baby is the most effective treatment, although some women may experience worsening symptoms before they get better.

8. Lymphedema

Lymphedema is a type of swelling that affects the soft tissues in the arms or legs, including the ankles. It is due to a buildup of a fluid called lymph. This is mainly composed of white blood cells, which help fight infection.

Lymphedema occurs when there is a blockage or some other damage to the lymphatic system. The lymphatic system is a network of tissues and organs that help rid the body of infection and keep fluids in balance.

Lymphedema can result from infections, cancer, and surgical removal of the lymph nodes. Some hereditary conditions can also cause lymphedema.

Damage to the lymphatic system is irreversible, so treatment aims to reduce swelling and prevent other symptoms.

Potential treatments include:

  • wearing pressure garments and bandages
  • increasing heart and respiration rate through exercise
  • getting a gentle massage from a therapist who is trained in treating lymphedema

9. Heart failure

Heart failure occurs when the heart can no longer pump blood as effectively as it should. There are three different types of heart failure: left-sided, right-sided, and congestive heart failure.

In right-sided and congestive heart failure, there is a reduction in blood flow out of the heart, causing blood to back up into the veins. This may lead to a buildup of fluid in tissues, including the legs and ankles.

Heart failure also affects the kidneys, reducing their ability to remove salt and water from the body. This further contributes to edema.

Although there is no cure for heart failure, there are many different treatment options.

A doctor may prescribe diuretic medications and suggest monitoring and reducing fluid intake. Both of these treatments can help reduce swelling in the ankles and legs.

10. Chronic kidney disease

woman exercising on stairs
Regular exercise can help maintain kidney function.

Chronic kidney disease refers to permanent kidney damage, which can worsen over time.

A person may not experience any symptoms until they are in the late stages of the disease, called kidney failure or end-stage renal disease (ESRD).

During ESRD, the kidneys struggle to remove waste and extra fluid from the body. This can lead to a range of symptoms, including swollen ankles.

The following lifestyle factors can also help maintain kidney function for as long as possible:

  • reducing salt and fat in the diet
  • maintaining a healthy weight
  • maintaining a healthy blood pressure
  • exercising for at least 30 minutes per day
  • quitting smoking
  • limiting alcohol
  • controlling blood sugar levels

11. Liver disease

The healthy liver produces a protein called albumin. Albumin prevents fluid from leaking out of the blood vessels and into surrounding tissues.

Very low levels of albumin due to liver disease can cause a buildup of fluid in the legs, ankles, and abdomen.

A doctor may prescribe medications and offer advice on certain lifestyle factors that could help prevent or slow further liver damage. Examples include:

  • exercising regularly
  • eating a healthful diet
  • limiting salt intake
  • avoiding alcohol

When to see a doctor

A person should see a doctor if they have:

  • heat or redness in the swollen area
  • swelling that worsens or does not improve
  • a fever
  • a sudden increase in swelling during pregnancy
  • a history of heart, kidney, or liver disease

Many cases of edema, or swollen ankles, will resolve themselves with proper home treatment.