Peripheral edema is swelling of your lower legs or hands. The cause may be simple, such as sitting for too long on a plane or standing for too long. Or it may involve a more serious underlying disease.

Edema occurs when something disrupts the usual balance of fluids in your cells. As a result, an abnormal amount of fluid accumulates in your tissues (interstitial space). Gravity pulls the fluid down into your legs and feet.

Peripheral edema is common in older adults and pregnant women, but it can occur at any age. It may affect one or both legs. If its onset is sudden and painful, you should see a doctor as soon as possible.

Symptoms of peripheral edema vary according to the underlying cause. In general, your legs or other affected area may:

  • look swollen and puffy
  • feel heavy, achy, or stiff
  • be bruised or discolored from an injury

Other symptoms may include:

  • skin in the swollen area that feels tight or warm
  • pitting (when you press on your skin for about five seconds, your finger leaves a dent in the skin)
  • swollen legs or feet that make it hard for you to walk
  • difficulty putting on stockings or shoes
  • weight that goes up from the fluid increase

Peripheral edema has a wide variety of causes. In general, if your edema subsides overnight, it indicates a milder cause. Constant peripheral edema, day and night, suggests a more difficult underlying cause.

Here are some common causes of peripheral edema, both temporary and systemic.

Temporary conditions associated with edema

Injury

A fracture, sprain, strain, or bad bruise in your leg, ankle, foot, or hand can result in swelling and pain. Inflammation in your lower leg may also be caused by an infection, a torn tendon or ligament, or a strained muscle.

Sitting or standing too long

Long plane flights or car rides may cause your legs and ankles to swell. This is common and not usually serious.

Sitting or standing for long periods as part of your work can also lead to peripheral edema.

Pregnancy

Eighty percent of pregnant women develop edema, usually in the hands, feet, and face. Pregnant women retain extra fluid that is needed by the fetus. In 50 percent of cases, the swelling occurs in the lower legs.

This peripheral edema is temporary and goes away after birth.

Hormonal changes

Fluid retention when you have your menstrual period is normal and may cause your legs and feet to swell. It occurs because of monthly hormonal changes.

Excessive salt intake

Eating too much salty food can cause your body to retain fluids, leading to edema.

Drug reactions

Peripheral edema can be a side effect of many drugs, usually because they involve increased water retention. The dosage and length of time you take these drugs affect the edema.

Drugs that may cause peripheral edema include:

Allergic reaction

Allergies may cause swelling in your arms and legs, although it more often affects other parts of your body. This type of swelling is called angioedema. It can be itchy if it involves hives. Triggers may be drugs, insect bites, or certain foods. Angioedema also may be hereditary.

Angioedema can be acute (sudden), requiring emergency treatment.

Idiopathic edema

“Idiopathic” means that the cause isn’t known. Idiopathic edema is most common in young women in their 20s and 30s. It involves weight gain and swelling of the face, trunk, and limbs.

It’s also associated with diabetes, obesity, and emotional problems.

Obesity

Excess weight causing pressure on veins can result in peripheral edema. Obesity may also lead to other causes of edema, such as obstructive sleep apnea or venous insufficiency.

Wearing tight clothing

Tight pants, panty hose, or leggings may promote edema in your legs.

Low altitude

If you move to a low altitude from a higher elevation, it can cause peripheral edema after about two weeks. The swelling decreases in time.

Diseases associated with edema

Venous insufficiency

Venous insufficiency means that the veins in your legs are damaged or weak, and don’t adequately pump blood up toward the heart. The blood then pools in your lower legs. You may have it in one or both legs.

Venous insufficiency is the most common cause of peripheral edema. It affects up to 30 percent of the population. When people over 50 have peripheral edema and systemic disease is ruled out, the cause is usually venous insufficiency. More women than men tend to have venous insufficiency. It can be an inherited condition.

Varicose veins are often present, but venous insufficiency can occur without them.

Initially, the edema will be soft and touching your leg briefly will leave a dent. In later stages, you may see changes in the pigmentation and elasticity of the skin. Your skin may become thicker and more fibrous.

The edema may get worse if you sit or stand for long periods, or if the weather is hot.

Blood clot

If edema occurs suddenly in one leg and your leg becomes painful, it could be caused by a blood clot in that leg. This is called deep vein thrombosis. It’s a serious condition and requires emergency medical help.

Heart failure

When the right side of your heart isn’t pumping effectively, blood can pool in your lower legs, causing edema. If the left side of your heart isn’t pumping effectively, fluid will accumulate in your lungs. Your breathing may be difficult, and you may also be fatigued.

Pericarditis

Pericarditis is the inflammation of the thin outer membrane surrounding your heart. It’s usually caused by a virus. But it can also result from autoimmune and other diseases.

The symptoms include peripheral edema and chest pain. Pericarditis usually resolves on its own.

Preeclampsia

Peripheral edema in your hands and feet is a symptom of preeclampsia, a serious complication of pregnancy. Preeclampsia can develop slowly or suddenly. A rise in blood pressure is a main symptom.

Edema isn’t considered a reliable indication of preeclampsia, because normal pregnancies also have peripheral edema.

Cirrhosis

When your liver is damaged by scarring, it can cause peripheral edema by putting pressure on the veins in your legs. The late stage of liver scarring is called cirrhosis.

Over time, hepatitis, alcohol misuse, and many other causes can damage the liver. The scars come from the liver’s attempts to heal itself. The scar buildup disrupts normal blood flow through the liver and its protein quality.

Pulmonary hypertension

Pulmonary hypertension is an often unrecognized cause of peripheral edema.

Pulmonary blood pressure is the pressure your heart needs to pump blood from the heart through the lungs. The pressure gets higher when the arteries in your lungs narrow as a result of lung disease, left heart failure, or sleep apnea.

Renal failure

Renal failure is also called chronic kidney disease or kidney failure. Peripheral edema is one of the symptoms.

When your kidneys are damaged, they don’t properly remove waste products and fluids from your blood. The buildup of excess fluids can lead to edema.

A 2016 study of 12,778 people admitted to a hospital with serious illnesses found that those with peripheral edema had a 30 percent higher risk for acute kidney injury.

Lymphedema

When your lymph system is damaged, fluid builds up in your tissues, causing peripheral edema. In the United States and other industrial countries, lymphedema can result from surgery to remove cancerous lymph nodes. This is called secondary lymphedema.

Primary lymphedema is less common and may be inherited. It can affect arms or legs.

Thirty percent of lymphedema cases are in both legs or both arms. Lymphedema also affects the feet and toes.

Lymphedema is usually painless and not tender. In its later stages, the skin looks darkened, thickened, and warty.

In developing countries, the most common cause of lymphedema is filariasis. This is a parasitic infection caused by the roundworm. It affects more than 90 million people.

Lipedema

Lipedema is an abnormal enlargement of both legs resulting from a misdistribution of fat under the skin. It affects up to 11 percent of women. It’s not always categorized as a true edema.

Inflammation

Arthritis, bursitis, gout, or Baker’s cyst may cause leg swelling.

Cellulitis

Cellulitis is a bacterial infection of skin tissue that causes red, painful sores and swelling. While it usually occurs on the legs, it can affect any area of skin on your body.

Malnutrition

A diet lacking in protein over a long period can result in fluid accumulation and peripheral edema in both legs.

Cancer and cancer treatments

Pelvic and other cancerous tumors may increase pressure on veins, leading to edema. Peripheral edema may also result from chemotherapy, radiation therapy, and other cancer treatments.

Sleep apnea

Obstructive sleep apnea may cause peripheral edema, even without the presence of pulmonary hypertension. One study of people with edema found that one-third of those who had apnea didn’t have pulmonary hypertension.

Other diseases

Several other diseases are associated with peripheral edema, including:

Treatment for peripheral edema depends on what’s causing the swelling. If an underlying disease is present, your treatment will be for that disease. In most cases, this will help the swelling.

For edema caused by lifestyle or temporary conditions, there are several remedies to provide relief:

  • Elevate your legs (or arms) above the level of your heart a few times a day. Sleep with a pillow under your legs at night.
  • Exercise. Your doctor or a physical therapist can suggest specific exercises to keep the muscles involved moving.
  • If you have to sit or stand a lot, take breaks to move around.
  • Wear compression stockings on the affected legs if your doctor recommends this.
  • Reduce your intake of salt.
  • Massage the affected area to gently push fluid in the direction of your heart.
  • Take horse chestnut. A supplement of horse chestnut seed extract taken twice a day may help leg circulation.
  • Lose weight if you’re overweight.
  • Take a diuretic (water pill) if your doctor prescribes it.

Peripheral edema can be caused by a serious disease or something more simple. In both cases, treatments are available to relieve the swelling and prevent further complications.

It’s best to see a doctor if there’s no apparent cause for the edema or you have other symptoms.