Ankle Swelling: Why Your Ankles Swell and What to Do

Why ankles swell

Gravity pulls fluid toward the lowest part of the body. Normally, leg muscles squeeze veins as you walk and one-way valves push blood back up to the heart. Fluid that leaks into tissues is drained by the lymphatic system. Ankles swell when:

• pressure in the veins rises (weak valves, heart failure, a clot)
• the blood holds less fluid because of low protein (kidney or liver disease, malnutrition)
• the body retains salt and water (kidney disease, hormones, medicines)
• the lymph system is damaged (lymphedema)
• local inflammation from an injury, infection or arthritis

Pitting edema leaves a dent when you press a finger into the swollen skin for 5 seconds. It is typical of fluid buildup. Swelling that does not pit is more typical of lymphedema or thyroid-related swelling.

Swelling in both ankles: common causes

Everyday causes

• standing or sitting for long periods, including long flights and car journeys
• hot weather, which widens blood vessels
• being overweight
• the premenstrual phase of the cycle
• pregnancy, especially in the third trimester. Gradual swelling of the feet and ankles is normal; sudden swelling of the face and hands is not

Venous insufficiency

Chronic venous insufficiency is the most common medical cause in middle-aged and older adults. Damaged vein valves let blood pool in the lower legs. Swelling is worse by evening and better in the morning, often with varicose veins, aching, itching, brown staining of the skin above the ankle and, eventually, ulcers.

Medicines

• calcium channel blockers for blood pressure, especially amlodipine
• NSAIDs such as ibuprofen
• steroids and estrogen, including some contraceptive pills and HRT
• some diabetes drugs (pioglitazone)
• some antidepressants and gabapentin or pregabalin

Do not stop a prescribed medicine without talking to your doctor.

Heart failure

When the heart pumps weakly, pressure backs up in the veins. Heart failure causes swelling of both ankles that creeps up the legs, with breathlessness on exertion or lying flat, tiredness and rapid weight gain (more than 1 kg or 2 lb in a day, or 2 kg or 5 lb in a week).

Kidney disease

Kidney disease, especially nephrotic syndrome, causes swelling of the ankles and puffiness around the eyes in the morning, sometimes with foamy urine.

Liver disease

Cirrhosis lowers blood protein (albumin) and raises pressure in abdominal veins, causing ankle swelling plus a swollen belly, jaundice and easy bruising. See liver disease.

Other causes

• an underactive thyroid
• low protein from malnutrition or gut disease
• lymphedema after cancer surgery or radiotherapy, or present from birth
• lipedema, a fat distribution disorder in women that spares the feet

Swelling in one ankle: common causes

How doctors find the cause

A doctor will ask when the swelling started, whether it affects one or both sides, whether it goes down overnight, and about breathlessness, medicines, pregnancy, injury and weight change. They will press for pitting, look at the skin and veins, listen to your heart and lungs, and check your abdomen.

Tests depend on the clues:

• Blood tests: kidney and liver function, albumin, blood count, thyroid, and BNP for heart failure
• Urine test for protein
• Doppler ultrasound for a DVT or vein valve problems
• D-dimer blood test when a clot is possible
• Echocardiogram and ECG for the heart
• X-ray after an injury

Treatment and home care

Treat the cause first: blood thinners for a clot, diuretics and heart medicines for heart failure, antibiotics for cellulitis, medicine changes for drug-related swelling.

For swelling from standing, heat, pregnancy or vein problems:

• Raise your legs above heart level for 20 to 30 minutes, 3 or 4 times a day, and when sleeping if possible.
• Move. Walk, and flex your ankles regularly on long journeys. Calf muscles pump fluid back up.
• Compression stockings reduce venous swelling. Check with a doctor first if you have diabetes, numb feet or poor circulation in the arteries.
• Cut down on salt, which holds water in the body.
• Lose weight if you are carrying extra.
• Protect the skin: moisturize and treat any cuts promptly, since swollen skin heals slowly.

For a sprain: rest, ice for 15 to 20 minutes at a time, a compression bandage and elevation for the first 48 hours, then gradual movement.

Do not take "water pills" (diuretics) without a diagnosis. They do not help venous swelling much and can cause dehydration and low potassium.

Frequently asked questions

When should I worry about ankle swelling?

Worry if one ankle swells suddenly with calf pain or redness, if swelling comes with breathlessness or chest pain, if you are pregnant and swelling is sudden with headache or vision changes, or if swelling keeps getting worse. These need same-day or emergency care.

Why are my ankles swollen at the end of the day?

Gravity pulls fluid into the lower legs when you stand or sit for hours, especially in heat. If it settles overnight, it is usually harmless or due to mild vein weakness. Swelling that lasts into the morning needs checking.

Can heart problems cause swollen ankles?

Yes. Heart failure causes fluid to back up into the legs, producing swelling in both ankles. It usually comes with breathlessness, tiredness, reduced exercise tolerance and rapid weight gain. Anyone with new ankle swelling and breathlessness should see a doctor promptly.

What does swelling in one ankle mean?

It usually means a local problem: a sprain or fracture, a blood clot in the leg, a skin infection, gout or arthritis. A clot is the most important to rule out, especially if the calf is painful or you recently had surgery, travel or immobility.

Can amlodipine cause ankle swelling?

Yes. Ankle swelling is a common side effect of amlodipine and other calcium channel blockers, and it is more likely at higher doses. It is not dangerous in itself, but tell your doctor, who may change the dose or medicine. Do not stop it on your own.

What is the fastest way to reduce swollen ankles?

For harmless swelling, lie down and raise your legs above heart level, move your ankles and walk regularly, and wear compression stockings if suitable. Reducing salt helps over days. Swelling from a clot, heart, kidney or liver problem needs medical treatment.