Injury, infection, and underling health conditions can all cause swelling in the legs and ankles.

Some causes of this swelling, such as standing or walking for long periods, are generally harmless. However, sudden or chronic swelling in the legs and ankles can indicate a health problem.

This article describes various causes of swollen legs and ankles and some of the treatment options.

A person may experience swelling in their legs and ankles for a range of reasons, including those below.

Heart failure

Heart failure is one of the most common causes of swollen legs and ankles.

If the heart is unable to pump blood around the body effectively, blood can build up, causing swelling known as edema. For people with heart failure, is common for edema to occur in the lower legs, ankles, and feet.

Treatment

Heart failure has no cure, but self-care strategies and ongoing treatments can help manage the condition.

Treatment options include:

Many people living with heart failure require ongoing support from a cardiologist.

Learn more about heart failure and swollen feet here.

Liver disease

The liver produces albumin, a protein that prevents fluid from leaking out of blood vessels and into surrounding tissues. A diseased liver does not produce enough albumin. As a result, fluid can pool in the legs, ankles, and feet.

Most people with liver disease have no symptoms until severe liver damage or cirrhosis develops.

Treatment

The only cure for chronic cirrhosis is a liver transplant. But with other approaches, doctors aim to manage the disease, relieve any symptoms, and prevent complications.

If swollen legs result from cirrhosis, a doctor may prescribe diuretics, such as spironolactone (Aldactone) or furosemide (Lasix). They may also recommend a low-sodium diet, which can help alleviate fluid retention.

Kidney disease

The kidney’s main role is to regulate the amount of water in the body and balance levels of salt and other minerals in the blood.

Diseases can severely damage the kidneys, keeping them from filtering the blood effectively and excreting fluid and other waste through the urine. This can lead to a buildup of waste in the lower legs and ankles.

Some other early signs and symptoms of kidney disease include:

Treatment

The treatment for kidney disease depends on its cause.

The damage may result from a medical condition, such as high blood pressure or diabetes. Doctors prescribe medications to manage these conditions and slow the rate of kidney disease.

In some cases, chronic kidney disease progresses to kidney failure. At this stage, a person needs dialysis or a kidney transplant.

Injury to the foot or ankle

An injury to the foot or ankle could cause swelling in the ankle and lower leg. One of the most common injuries in this area is a sprained ankle.

This can result from a simple misstep when walking, playing sports, or working out. It happens when the ligaments that connect the ankle to the foot and leg are pulled out of alignment.

A sprained ankle can cause pain and limited mobility.

Treatment

The most common approach to foot or ankle injuries is the RICE method. RICE stands for:

  • Rest: Resting the affected ankle helps prevent further damage.
  • Ice: Applying ice or an ice pack wrapped in a towel helps numb the pain and reduce swelling. Apply it for 15–20 minutes at a time at least three times a day.
  • Compression: Wearing a compression bandage helps limit swelling.
  • Elevation: Elevating the foot or ankle above level of the heart helps reduce swelling.

Infection

An infection in the feet, ankles, or lower legs can cause swelling in the area. Cellulitis is one type of skin infection that commonly affects the lower limbs.

People with diabetes have an increased risk of infection in their feet. It is important to inspect the feet regularly for bruising, cuts, and scrapes.

A person with diabetes and an untreated infection in a foot or leg may develop gangrene. Gangrene involves tissues dying as a result of severe infection or reduced blood supply.

Treatment

The treatment for a foot, ankle, or leg infection depends on its type and severity. If the infection is bacterial, a doctor tends to prescribe antibiotics.

If the infection has resulted in gangrene, surgery to remove the damaged area may be necessary.

Lymphedema

Lymphedema involves excess fluid accumulating in tissues, causing swelling. It occurs when lymph nodes are damaged or have been removed.

The lymph nodes are glands that are part of the immune system, and they help remove fluid. If lymph nodes in the pelvis are damaged or absent, it can cause fluid to build up in the legs.

A person with lymphedema may have a feeling of heaviness or swelling in their legs or other affected areas.

Treatment

Treatment options for lymphedema include:

  • bandaging the affected leg
  • wearing compression stockings
  • massaging the lymph nodes to encourage drainage
  • performing gentle exercises to encourage drainage
  • caring for the skin to reduce the risk of infection and associated lymphedema

Venous insufficiency

The veins in the legs contain valves that prevent blood from flowing backward. Venous insufficiency involves these valves not functioning effectively. As a result, the veins no longer transport enough blood to the heart.

When a person has venous insufficiency, blood becomes trapped in the soft tissues of the lower legs and ankles. A person may also have:

  • skin ulcers
  • changes in skin color
  • infection

Treatment

The treatment for venous insufficiency aims to restore healthy blood flow. This may involve:

  • not crossing the legs when sitting or lying down
  • elevating the legs
  • getting more regular exercise
  • wearing compression stockings

A doctor may also recommend medications, and the type depends on the severity of the venous insufficiency and the person’s overall health.

Blood clot

A blood clot in a leg can cause the ankle and leg to swell. This may only happen on one side of the limb.

There are two main types of blood clot. Superficial blood clots occur in a vein closer to the surface of the skin. Deep vein thromboses (DVTs) occur in a vein deeper within the body.

A person needs immediate medical attention if they have any of these symptoms of a blood clot:

  • swelling and pain in one leg
  • a heavy ache in the leg
  • an area of warm skin on the leg
  • an area of red or flushed skin behind and below the knee
  • a change in the color of the leg
  • a low fever

Sometimes, a piece of the clot breaks loose and travels to the heart, lungs, or brain. This can be life threatening without treatment.

The risk of a blood clot is highest for people who:

  • are pregnant
  • are immobile due to surgery or hospitalization for another reason
  • have obesity
  • are older adults

Treatment

Oral anticoagulants are the primary treatment for blood clots. These medications help prevent clots from getting bigger and help prevent new clots from forming.

Warfarin is the most common oral anticoagulant. Other oral medications include:

However, the high cost of these medications can limit access to them.

Medication side effects

Some medications can cause a person’s ankles or legs to swell. Examples of these include:

Treatment

Contact a doctor about any side effects of medication. They may lower the dosage or recommend a different drug. Always receive the approval of a doctor before stopping a treatment.

It is common for some foot and ankle swelling to occur during pregnancy, and this can be worse for people who spend a lot of time on their feet.

But sudden or severe swelling in the legs, ankles, or feet can be a sign of preeclampsia — a sudden rise in blood pressure that can be dangerous for the pregnant person and their fetus.

Other signs and symptoms of preeclampsia include:

It is crucial to let a healthcare professional know about these and any other unusual symptoms during pregnancy. Preeclampsia subsides after delivery.

Older adults are more likely to have chronic venous insufficiency and chronic kidney disease. Both often lead to swelling in the lower extremities.

Also, from the age of 40 onward, a person has an increased risk of developing DVT.

In addition, because some older adults have reduced mobility, they may be more susceptible to dependent edema. This is swelling in the lower limbs due to the pull of gravity, an it is more common in people with lower activity levels.

Contact a healthcare professional if any of these symptoms develop in one or both legs or ankles:

  • sudden swelling
  • unexplained swelling
  • additional symptoms, such as shortness of breath, fever, and pain

A doctor can help diagnose the underlying issue, which usually helps relieve the swelling.

In some cases, self-care strategies can help prevent or relieve swelling in the legs and ankles. These include:

  • frequently checking the feet for bruises, cuts, and scrapes, especially for people with diabetes
  • getting regular exercise
  • having a healthy diet that promotes heart, kidney, and liver health
  • avoiding contact sports that can injure the legs and ankles

Swelling in the legs and ankles can be normal in some cases, but if it is sudden, unexplained, or accompanied by additional symptoms, contact a healthcare professional. Some health issues that result in this swelling can be life-threatening without treatment.

It is not always possible to prevent swelling in the legs and ankles. However, exercising regularly, having a healthy diet, and protecting the legs from injuries can help.