Foot and Ankle Swelling
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026
Swollen feet and ankles are usually caused by oedema (say ee-DEE-ma), which is fluid collecting in the tissue under your skin. It is very common. The most common cause in people who are up and about is standing or sitting for long periods. Swelling can also come from vein problems, some medicines, injuries, infections, blood clots or heart, kidney or liver conditions. Because the cause decides the treatment, finding it matters more than treating the swelling alone. Many people improve once the cause is dealt with, but some causes need long-term care.
What is it?
Most swollen feet and ankles are caused by oedema. This is fluid that builds up in the tissue under your skin, often in the lower legs and ankles. Your shoes may feel tight, your socks may leave deep marks, and the skin may look stretched or puffy.
Some swelling is "pitting". If you press the swollen area gently with a finger for a few seconds, the skin holds the dent for a little while. Whether it pits, and how it looks and feels, helps your practitioner work out the cause.
Swelling in the lower legs is very common. It is often harmless, such as after a long day on your feet. But it can also be a sign of a more serious condition, so it is worth finding out why it is happening.
What can cause it?
There are many causes. These are the main ones, starting with the most common.
- Standing or sitting for long periods, or not moving much. This is the most common cause in people who are up and about. Fluid settles in your lower legs and feet.
- Weak leg veins (chronic venous insufficiency). The veins struggle to return blood to the heart. The swelling pits, and the skin on the lower leg can turn brownish-red and feel firm.
- Medicines. Swelling that starts soon after a new medicine, such as some blood pressure tablets, may be caused by it.
- Heart, kidney, liver or thyroid conditions, or low protein in the blood. The swelling is usually in both legs, doesn't hurt, and builds up over days, weeks or months.
- A blood clot in a deep leg vein (deep vein thrombosis, or DVT). The swelling comes on within about three days, is usually in one leg, and is often tender.
- Skin infection (cellulitis). The swelling comes on quickly and is tender, with redness, heat, pain and sometimes a fever.
- Lymphoedema. This happens when the lymphatic system (the body's drainage network) isn't working properly. Early on, the swelling can be soft, come and go, be worse during the day and ease overnight. Later it usually doesn't pit, and without treatment it becomes more severe and lasts.
- Post-thrombotic syndrome. This is long-lasting leg swelling and skin changes that can follow a DVT.
- Injury. A sprain or strain, an insect bite or sting, a leg injury or surgery can all cause swelling. After an injury it usually appears within about three days.
- Other things. Pregnancy, thyroid problems, being overweight, a lot of salt in your diet, and a pattern of swelling that comes and goes in cycles (idiopathic cyclic oedema).
Who gets it?
Anyone can get swollen feet and ankles. You are more likely to notice it if you stand or sit for long hours, are pregnant, are carrying extra weight, take certain medicines, or have varicose veins or a thyroid, heart, kidney or liver condition.
After a DVT, 20 to 50 per cent of people go on to develop post-thrombotic syndrome. Severe cases, which can include leg ulcers (open sores that heal slowly), affect 5 to 10 per cent of people.
How is the cause found?
Your practitioner will start by asking questions. They will want to know when the swelling began, whether it is in one leg or both, whether it hurts, whether it eases overnight, whether you have had an injury, and which medicines you take. Their questions and examination are enough to find the cause in most people. Extra tests are needed for only some.
They will look at both legs and compare them. They will press the swollen area to see if it pits, look at the skin colour and texture, check for varicose veins, ulcers and tenderness, and may check the blood flow to your legs (using the ankle-brachial index, a comparison of blood pressure in your ankle and arm). This check matters before any compression is used.
If a heart, kidney, liver or thyroid cause is possible, you may have blood and urine tests, and heart tests such as an ECG (a recording of your heart's rhythm) or a chest X-ray. If a clot or vein problem is possible, you will need an ultrasound scan. A suspected clot needs a scan promptly, usually at a hospital.
Some general patterns help. One swollen leg usually points to a local problem such as an infection or a clot. Two swollen legs more often point to something affecting the whole body. These are guides only, and there is overlap. Pitting, for example, can happen with both vein problems and heart failure.
Treatment
Treatment depends on the cause. Finding and managing the cause matters more than treating the swelling alone, because swelling can be a sign of heart, liver or kidney disease.
Looking after it at home
For long-standing swelling, these steps are commonly advised:
- Keep your feet and ankles moving. This is described as the most important thing you can do. Walk little and often rather than going for one long walk.
- Raise your legs on a chair or pillows when you can.
- Avoid standing or sitting in one position for long periods.
- Wear wide, comfortable shoes with a low heel and a soft sole. Avoid tight clothes and tight footwear.
- Wash, dry and moisturise your feet to help avoid infection.
Treatment from your podiatrist
Your podiatrist can help look for the cause, check your skin, feet and shoes, and check blood flow to your legs. If your swelling is from weak leg veins, graded compression stockings (stockings that squeeze most at the ankle) are the main treatment. They are usually fitted for you, and the right strength matters.
Compression is not safe for everyone. It shouldn't be used if the blood flow to your legs is poor, as it can cause skin damage and, in the worst cases, loss of a limb. It also isn't suitable if you have a leg or foot infection, a suspected blood clot or very severe swelling, or severe heart failure. If you have nerve damage or fragile skin, extra care is needed, with padding, careful fitting, lighter pressure and early check-ups. If you wear compression long term, you will need regular nerve checks, because nerve damage has been reported, causing numbness or foot drop (difficulty lifting the front of your foot). When compression is used correctly, serious problems are very rare.
After a recent ankle sprain, early exercise and a proper brace or tape work better than a compression bandage or tubigrip. Resting the ankle in a boot or splint should be kept to no more than 10 days before you start exercising. Anti-inflammatory medicines, taken by mouth or put on the skin, can reduce pain and swelling in the short term. Care is needed, because they can cause complications and may slow natural healing. This advice was developed for athletes, so it may not suit everyone. Your practitioner can tailor it for you.
Other options
If you have long-lasting leg swelling and keep getting cellulitis, compression helps. In adults with this problem, cellulitis came back in 15 per cent of people wearing compression, compared with 40 per cent of people who weren't.
After a DVT, compression can ease symptoms during the first year. It hasn't been shown to clearly prevent skin changes, and the symptom benefit is not clear after the first year.
If you have lymphoedema, you may be referred to a lymphoedema specialist, who can teach you how to manage and treat it.
Will it get better?
It depends on the cause. Swelling from a long day on your feet usually settles with movement and rest. Swelling from an injury, a medicine or an infection should ease as the cause is dealt with.
Some causes are long-term. Lymphoedema doesn't go away, and without treatment its swelling usually becomes more severe and lasts. Post-thrombotic syndrome after a DVT can also be long-lasting. With the right care, these can be managed.
After an ankle sprain, starting guided exercise early lowers the chance of hurting the ankle again.
Preventing it
Keeping active is the key. Move your ankles often, especially on long flights, at a desk or on your feet at work. Walk little and often, raise your legs when you rest, and break up long periods of sitting or standing.
Wear wide, comfortable, low-heeled shoes, avoid tight clothing and footwear, and keep your feet clean and moisturised. After an ankle sprain, start guided exercise early and ask about a brace or tape. If swelling returns or changes, book a review. It isn't yet clear how well these everyday steps stop swelling from coming back, but they are sensible ways to look after your legs.
When to see a podiatrist
Book an appointment if
See your GP soon if your swelling doesn't clear by itself, or if both of your legs, ankles or feet are swollen and it hasn't improved after a few days of home care, it is getting worse, or you have a heart, kidney or leg vein condition. Book an appointment with your podiatrist if you want your feet, skin and shoes checked, you'd like advice on compression stockings, or swelling keeps coming back or changes.
Seek prompt assessment if
Call your local emergency number if you suddenly become short of breath, have chest pain, or cough up blood, especially with a painful, swollen leg. Don't drive yourself. Also call if swelling comes with fast breathing, confusion or feeling faint.
See your GP or another doctor today if swelling comes on suddenly, especially in one leg, or if your swollen leg is red, hot, painful or getting more swollen, or you have a high temperature or feel hot, cold or shivery. Redness can be harder to see on brown and black skin. A blood clot or an infection can cause these signs, and both need assessing without delay. Don't wait for swelling to clear if you also feel breathless: see a doctor today. Also see a doctor today if a varicose vein is bleeding, so you can be referred to a vein specialist. If your GP can't see you today, go to an urgent care clinic or an after-hours GP.
Frequently asked questions
How do I check if my swelling is pitting?
Press gently on the swollen area with a finger for a few seconds, then let go. If a dent stays for a little while, it is pitting oedema. Tell your practitioner what you find, along with whether one foot or both are swollen and whether it eases overnight. These details help them work out the cause.
Can my medicines cause swollen ankles?
Yes, they can. Some blood pressure medicines, contraceptive pills, hormone therapy, antidepressants and steroids are linked to swelling. Bring a list of everything you take, including anti-inflammatories, to your appointment. Your practitioner can then see whether a medicine could be playing a part.
Are rest, ice, compression and elevation enough for a sprained ankle?
On their own, they haven't been shown to improve pain, swelling or how well the ankle works after a sprain. Starting guided exercise early, with a proper brace or tape, gives better results. Ask your practitioner for an exercise plan that suits your ankle.
Is swelling in one leg more serious than in both?
It can be. Swelling in one leg is more often linked to a local problem, such as an infection or a blood clot. If it comes on suddenly in one leg, see your GP or another doctor today. Swelling in both legs is more often linked to something affecting the whole body, but it still needs a review if it doesn't settle.