Below are eight potential causes of swollen legs and ankles.

1. 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 causes of injuries to this area is a sprained ankle.

A sprained ankle can occur as a result of a simple misstep, or a sports or exercise injury. It happens when the ligaments that connect the ankle to the foot and leg are pulled out of alignment.

A person who has a sprained ankle may experience pain and limited mobility in the ankle or foot.

Treatment

The most common treatment for foot or ankle injuries is the RICE procedure. RICE is an acronym which stands for:

  • Rest: Resting the affected foot helps to prevent further damage.
  • Ice: Applying ice to the injury helps to numb pain and reduce swelling. People should wrap ice in a towel before applying it to the skin. Ideally, people should apply the ice pack for 10-20 minutes, three or more times per day.
  • Compression: Wearing a compression bandage will help to reduce swelling.
  • Elevation: Elevating the foot or ankle above heart level will help reduce swelling.

2. Infection

An infection in the feet, ankles, and lower legs can cause swelling in this area.

People who have diabetes are at increased risk of developing an infection in their feet. They should, therefore, inspect their feet regularly for bruising, cuts, and scrapes.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), people who have diabetes and an untreated infection in the foot or legs can develop gangrene. Gangrene is where body tissues die as a result of severe infection or reduced blood supply.

Treatment

The treatment for a foot infection depends on its severity. In most cases, a doctor will prescribe antibiotics to treat the bacterial infection.

If the infection has resulted in gangrene, the person may require surgery to remove the damaged toes or foot.

3. Lymphedema

Lymphedema is a condition in which excess fluid accumulates in the body’s tissues, causing swelling. Lymphedema occurs when a person’s lymph nodes become damaged or are absent due to surgical removal.

The lymph nodes are glands that make up part of the body’s immune system. They are responsible for helping to remove fluids from various parts of the body. If the lymph nodes in the pelvis are damaged or absent, this can cause fluid to build up in the legs.

A person who has lymphedema may experience a feeling of heaviness or swelling in their legs or other affected body parts.

Treatment

According to Memorial Sloan Kettering Cancer Center, some 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
  • practicing good skincare to reduce the risk of infection and associated lymphedema

4. Venous insufficiency

The veins within a person’s legs contain special valves that prevent blood from flowing backward. Venous insufficiency is a condition in which these valves no longer function properly. As a result, the veins no longer transport adequate amounts of blood from the legs back up to the heart.

When a person has venous insufficiency, their blood flows back down the legs and becomes trapped in the soft tissues of the lower legs and ankles.

A person with venous insufficiency may also experience:

  • skin ulcers
  • changes in skin color
  • infection

Treatment

According to Stanford Health, the treatment for venous insufficiency involves returning blood flow to the legs. This may involve:

  • avoiding crossing the legs when sitting or lying down
  • elevating the legs
  • performing regular exercise
  • wearing compression stockings

People may also receive medications to treat venous insufficiency. The type of medication a person gets will depend on the severity of their condition and their overall health.

5. Blood clot

A blood clot in the legs can cause a person’s ankles and legs to swell. Blood clots in the legs tend to develop on one side of the limb.

There are two main types of blood clot:

  • superficial blood clots, which occur in a vein closer to the surface of the skin
  • deep vein blood clots or “deep vein thromboses” (DVTs), which occur in a vein deep within the body

A person should seek immediate medical attention if they experience any of the following symptoms of a blood clot:

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

Sometimes, a piece of the clot breaks loose and travels to the heart, lungs, or brain. This can be life-threatening if left untreated.

Treatment

Typically, people who have a blood clot receive anticoagulant medications, which help prevent clots from getting bigger. They also help prevent new clots from forming.

Two common anticoagulant medications are heparin and warfarin.

6. Liver disease

The liver produces albumin, which is a protein that prevents fluid from leaking out of blood vessels and into surrounding body tissues.

A diseased liver does not produce enough albumin. Liver disease can, therefore, cause fluid to pool in the legs, ankles, and feet.

Most people who have liver disease do not experience symptoms until they have developed severe liver damage, or cirrhosis.

Treatment

The only cure for liver cirrhosis is a liver transplant. However, treatment aims to manage the disease and prevent further complications. Treatments can also help to alleviate some of the symptoms of cirrhosis.

People who experience swollen legs as a result of cirrhosis may require diuretics, such as spironolactone or furosemide. People may also need to reduce their dietary intake of salt, as doing so can alleviate fluid retention.

7. 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.

Kidneys that are severely damaged by disease are unable to filter the blood effectively and excrete fluid and other waste products through urine. This can lead to a buildup of fluid and other waste products within the body, including in the lower legs and ankles.

Some other early warning signs of kidney disease include:

Treatment

The treatment for kidney disease depends on its underlying cause. According to the National Kidney Foundation, some causes, such as urinary tract infections and kidney stones, respond well to treatment.

Kidney disease may also occur as a result of an underlying medical condition, such as high blood pressure or diabetes. In such cases, a doctor will prescribe medications to manage these conditions and slow the rate of kidney disease.

In some cases, chronic kidney disease may progress to kidney failure. At this stage, a person will require dialysis or a kidney transplant.

8. Medication side effects

In some cases, medications can cause a person’s ankles or legs to swell. Some medications that may cause swelling as a side effect include:

If a person experiences side effects from their medications, they should talk to their doctor. The doctor may suggest lowering the dosage of the medication or switching to a different drug altogether.

People should not stop taking their medication without the approval of their doctor.