Swollen feet and ankles: common causes and when it’s serious

When is ankle swelling serious?

Use this as a quick check. If you’re unsure, it’s always reasonable to get seen.

Call 911 or go to the emergency room if swelling comes with:

• chest pain or pressure, especially with sweating, dizziness or nausea
• sudden or severe shortness of breath, or coughing up blood or pink, frothy mucus
• confusion, fainting, or yellow skin or eyes with severe tiredness

Don’t drive yourself to the hospital if you have any of these. Call 911.

Get seen the same day if you have:

• sudden swelling in one leg, especially with calf pain, warmth or redness (possible blood clot)
• swelling that’s red, hot and painful, or comes with a fever (possible infection)
• sudden or severe swelling during pregnancy, especially with a headache, vision changes or swelling of the face or hands (possible preeclampsia)
• swelling after an injury and you can’t put weight on the foot
• weight gain of more than 2 to 3 pounds in a day, or 5 pounds in a week, with swelling
• swelling that’s getting worse quickly, especially if you have heart or kidney disease

If you can’t be seen by a doctor the same day, go to an emergency room.

Book a visit soon if:

• swelling is new and you don’t know why
• swelling slowly gets worse over several days or weeks
• it doesn’t go down overnight, or keeps coming back
• pressing the swollen area leaves a dent
• it started after you began a new medicine
• you also notice foamy urine, passing less urine, puffy eyelids, breathlessness or skin changes around the ankles
• you have diabetes and notice new swelling, skin breakdown or color changes on your feet

What swollen ankles look like

Swelling in the feet and ankles, called peripheral edema, is extra fluid trapped in the tissues. Because gravity pulls fluid downward, it shows up in the feet and ankles first. You might notice:

• sock marks that stay for a while, or shoes that feel tight by evening
• shiny, stretched skin over the top of the foot
• a heavy, tight or achy feeling
• a dent that stays for a few seconds when you press the swollen area (called pitting)

Not all swelling is fluid. Swelling from an injury, gout or arthritis tends to be in one spot, and it’s often painful, warm or red and hurts when you move the joint.

Two clues: does it go down overnight?

Clue 1: your ankles swell during the day but look normal in the morning. Gravity or a medicine is usually the cause. Sitting or standing for long periods lets fluid settle in your legs, and some blood pressure medicines, such as amlodipine, can make it worse. Swelling that goes down overnight is usually less concerning, although it doesn’t completely rule out a heart or kidney problem.

Clue 2: your swelling gets worse every day. If your ankles are more swollen each day, don’t go back to normal overnight, or you’re gaining weight quickly, your body may be holding on to too much fluid. That can be a sign that your heart, kidneys or liver aren’t working as well as they should, or that a circulation problem is getting worse. Book a visit with your doctor.

Keep track of whether the swelling goes away overnight or builds from one day to the next. It’s one of the first things your doctor will ask.

Everyday causes of swollen feet and ankles

These are the most common causes. They usually affect both feet, build up through the day and improve overnight.

Long periods of sitting or standing

Your calf muscles act as a pump that pushes blood and fluid back up your legs every time you walk. When you sit at a desk, stand at a counter or stay still on a long drive, that pump slows down and fluid pools around your ankles.

Travel and long flights

Hours of sitting in a cramped seat is a classic cause. Before and during a long trip:

• drink water and skip very salty meals
• do ankle pumps and circles every 30 to 60 minutes, and walk the aisle or stop the car when you can
• consider compression socks, if they’re safe for you
• take a short walk and raise your legs after you arrive

Swelling in just one leg after a long trip needs to be checked the same day, because long travel raises the risk of a blood clot.

Salty food

Salt makes your body hold on to water. A single salty meal, such as takeout, canned soup, deli meat or chips, can cause noticeable puffiness within hours. Our guide to foods and drinks that reduce swelling explains what to eat and what to cut back on.

Hot weather

Heat widens your blood vessels to help you cool down, which lets more fluid leak into the tissues. Many people notice more swelling in summer.

Hormones and pregnancy

Fluid retention can come and go with the menstrual cycle, perimenopause, birth control pills and hormone therapy. In pregnancy, more blood volume and pressure from the growing womb on the pelvic veins make swollen feet very common, especially in the last trimester.

Mild swelling in pregnancy is normal. Sudden or severe swelling, or swelling with a headache, vision changes, pain under the ribs or puffiness in the face and hands, is not. Call your doctor or midwife right away.

Extra body weight

Extra weight puts more pressure on the veins in your legs, which makes it harder for fluid to drain back up.

Minor injuries and bites

A sprain, a knock or an insect bite can cause swelling in one area. If it’s clearly linked to an injury and improving day by day, that’s usually part of healing.

Medicines that can cause swelling

Several common medicines list ankle swelling as a side effect:

Don’t stop a prescribed medicine on your own. If swelling started after a new medicine or a dose change, tell your doctor. There’s often an alternative.

Medical causes that need a doctor

When swelling doesn’t go away, keeps getting worse or comes with other symptoms, it can be a sign of a problem elsewhere in the body.

Vein problems (chronic venous insufficiency)

The veins in your legs have one-way valves that keep blood moving up toward the heart. When the valves weaken, blood pools and fluid leaks into the tissues. It’s one of the most common causes of long-term ankle swelling. Signs include:

• swelling that’s worse by evening and better in the morning
• heavy, aching legs
• varicose veins
• brownish skin, itching or thickened skin around the ankles
• in advanced cases, sores (ulcers) near the ankle that are slow to heal

Heart failure

When the heart can’t pump well, fluid backs up into the veins and leaks into the legs, and sometimes the lungs and belly. Signs include:

• swelling that builds over days or weeks
• shortness of breath with activity or when lying flat
• waking up at night short of breath
• tiredness and less ability to exercise
• quick weight gain from fluid

With treatment, many people with heart failure live full, active lives, which is why it’s worth getting checked early.

Kidney disease

Your kidneys balance salt and water in your body. When they aren’t working well, fluid builds up. Damaged kidneys can also leak protein (albumin) into the urine, and without enough albumin in the blood, fluid seeps into the tissues. Signs include:

• puffy eyelids or face in the morning, with ankle swelling later in the day
• foamy or bubbly urine
• passing less urine, or getting up at night to urinate
• high blood pressure that’s hard to control
• tiredness, itchy skin, muscle cramps or poor appetite in later stages
• swelling that keeps getting worse

Kidney disease often has no symptoms early on. If you have diabetes, high blood pressure or a family history of kidney disease, ask your doctor about a blood test (creatinine and eGFR) and a urine test for protein. These simple tests can show whether your kidneys are contributing to the swelling. Evolve Health’s nephrology specialists evaluate kidney-related swelling, protein in the urine and chronic kidney disease when a closer look is needed.

Liver disease

The liver makes albumin, the protein that keeps fluid inside your blood vessels. With cirrhosis or other long-term liver disease, albumin drops and fluid leaks into the legs and belly. Signs include:

• a swollen belly as well as swollen ankles
• yellow skin or eyes
• dark urine or pale stools
• easy bruising
• itching, confusion or changes in sleep

Blood clot (deep vein thrombosis)

A blood clot in a deep vein of the leg blocks blood flow and causes sudden swelling, usually in one leg. It’s an emergency because the clot can break off and travel to the lungs. Signs include:

• sudden swelling in one leg
• pain or tenderness in the calf, often worse when walking
• warmth and redness
• recent surgery, a long trip, a cast, pregnancy, cancer or a past clot

Don’t massage a leg you think may have a clot. Get seen the same day, and call 911 if you also have chest pain or trouble breathing.

Lymphedema

The lymphatic system drains extra fluid from the tissues. When it’s damaged, for example after cancer surgery, radiation or repeated infections, fluid builds up. Lymphedema causes long-lasting swelling that doesn’t go down overnight, often includes the toes and top of the foot, and can make the skin thick and prone to infection.

Joint problems and injuries

Some ankle swelling comes from the joint itself rather than extra fluid in the body:

• Sprains and fractures cause swelling and bruising around the injury.
• Gout causes sudden, severe pain with redness and swelling, most often in the big toe but sometimes the ankle.
• Arthritis causes stiffness, pain and swelling in the joint.
• Tendon problems, such as a weakened tendon along the inside of the ankle, can cause swelling and arch pain. See our guide to inner arch pain.

This kind of swelling is usually painful and often affects one side. A podiatrist can find the cause and treat it.

Tests your doctor may order

Your doctor will start with questions: when the swelling started, whether it’s in one leg or both, whether it goes down overnight, and what other symptoms you have. Then they’ll examine your legs, heart and lungs, and check for pitting and skin changes. Depending on what they find, tests may include:

• blood tests for kidney function, liver function, protein (albumin), thyroid and blood count
• a urine test for protein
• a leg ultrasound to look for a blood clot or weak vein valves
• a D-dimer blood test when a clot is possible
• an ECG, chest X-ray or heart ultrasound (echocardiogram) if the heart may be involved

It helps to tell your doctor exactly what you’ve noticed, for example: “It’s been three weeks, it’s only my left leg, and it’s getting worse,” or “My ankles swell and I get short of breath lying down.” Taking photos of the swelling at different times of day is useful too.

What you can do at home

For mild everyday swelling without warning signs:

• Raise your feet above the level of your heart for 15 to 30 minutes, a few times a day.
• Move often. Walk, do ankle pumps and calf raises, and break up long periods of sitting.
• Cut back on salt for a few days.
• Try compression socks, if they’re safe for you. Ask your doctor first if you have diabetes, poor circulation or numb feet. Our compression socks guide explains how to choose them.
• Review your medicines with your doctor if the swelling started after a new prescription.
• Keep your weight in a healthy range, and wear comfortable, roomy shoes.

Don’t start water pills (diuretics), or drink extra fluids to treat swelling, unless a doctor tells you to.

Our guide on how to reduce swelling fast has step-by-step routines for after work, overnight and travel, and explains medical treatments. Swelling that keeps coming back deserves a check-up even if home care helps.

The bottom line

• Worse in the evening, better in the morning? Often gravity, circulation or a medicine.
• Getting worse from one day to the next? Book a visit with your doctor.
• Sudden swelling in one leg? Get seen the same day.
• Swelling with chest pain, severe trouble breathing or fainting? Call 911.

Swelling isn’t a disease in itself. It’s a sign that something in your body may need attention, and swelling that keeps coming back deserves an explanation, not just short-term relief. Evolve Health’s nephrology specialists look at kidney-related causes, and our podiatrists treat swelling from foot and ankle injuries and joint problems.