Why do I get swollen feet and ankles?

Swollen feet and ankles are usually caused by a build-up of fluid, called oedema.¹ Mild swelling often goes away on its own,² but it can also be a sign of something that needs prompt treatment. Here are the common causes and the warning signs to look out for.

What is swelling (oedema)?

The heart pumps blood to all parts of the body through the arteries, and it comes back through the veins. Some fluid from the blood normally seeps into the tissues, then drains back into the veins and the lymph vessels. If more fluid stays in the tissues than usual, that causes swelling.

The heart pumps blood away from itself, but it doesn't pump it back. Blood returns through the veins, helped by tiny one-way valves that keep it flowing up towards the heart.³ Because we stand on two feet, gravity works against us and pushes fluid down towards the ankles.⁴ Some swelling, such as around an injury, is a normal part of the body's repair process.

What causes it?

Hot weather

When you're hot, the small blood vessels dilate (get bigger) and let more fluid than usual leak into the surrounding tissues. Gravity pushes it down towards your ankles, so standing for long periods in hot weather can make them very swollen.⁴

Venous insufficiency

Venous insufficiency means the veins in your legs aren't working as well as they should. When the vein valves are damaged, blood can flow back down the leg and pool.³ Leaky vein valves are the most common reason for swelling in both ankles,⁴ and varicose veins become more common with age.³ Over time, chronic (long-term) venous insufficiency can change the colour of the skin around the ankles³ and lead to leg ulcers.⁵

The menstrual cycle

Some women get swelling in their feet and ankles as a normal part of their menstrual cycle.¹

Pregnancy

Some swelling is normal in pregnancy, especially later on and at the end of the day. Your body holds more water than usual, and the pressure of your growing womb affects blood flow in your legs.⁶

A sudden increase in swelling of your face, hands or feet can be a sign of pre-eclampsia, a serious condition.⁶,⁷ Contact your midwife, doctor or maternity hospital straight away, especially if you also have a bad headache, vision problems or pain below your ribs.⁶

Injury

When you injure your foot or ankle, for example by spraining it, you can get swelling from bleeding in the area and, afterwards, as your body repairs the damage.⁸

Infection

Infection triggers inflammation, which can include swelling. A skin infection called cellulitis can make the skin red, swollen, warm and painful, sometimes with a fever or swollen glands nearby.⁹ Get medical help urgently if the redness is spreading quickly or is very painful, or if you have a fever, especially if you have diabetes or a weakened immune system. Red streaks spreading from the area are another reason to see your doctor promptly.⁹

Blood clot (deep vein thrombosis, or DVT)

A DVT is a blood clot in a deep vein, usually in the calf or thigh. It's more likely after surgery, an injury or a long period of sitting still (such as a long-haul flight), and during pregnancy, but it can happen for no obvious reason.¹⁰ It usually causes pain and swelling, and the area may look red or have more noticeable veins, though some people have no symptoms.¹⁰ If you think you may have a DVT, see a doctor straight away. Your doctor may send you for an ultrasound scan to check.¹⁰

Medical conditions

Heart failure, kidney problems and liver disease can all cause fluid retention.¹,² See your GP if you have one of these conditions or are worried this could apply to you.

Medication side effects

Many medicines can cause swelling of the feet and ankles, and the amount varies from person to person. Examples include:¹,⁵

• some blood pressure medicines (calcium channel blockers such as amlodipine)
• steroids
• non-steroidal anti-inflammatory drugs (NSAIDs)
• some diabetes medicines
• hormones such as oestrogen (including the pill and some hormone replacement therapies) and testosterone
• some antidepressants
• gabapentin and pregabalin (used for nerve pain).

If you notice swelling after starting a medicine, don't stop it or change the dose yourself. Talk to your doctor or pharmacist first.¹

Lymphoedema

Lymphoedema is long-term swelling caused by a problem with the lymphatic system, the vessels and nodes that drain fluid from your tissues.¹¹ Primary lymphoedema comes from a problem with the lymphatic system itself and can be genetic; it's rare and usually starts in childhood or early adulthood. Secondary lymphoedema is more common and is caused by damage to the lymphatic system, for example after cancer surgery or radiotherapy that affects the lymph nodes.¹¹

Signs and symptoms

Swollen skin can look puffy, tight or shiny, and pressing on it for a few seconds may leave a dent. Swelling is often worse after sitting for a long time and at the end of the day, and your legs may feel heavy.¹

What can help?

If there's a medical cause for your swelling, your doctor will advise you. Some people need a diuretic (a "fluid tablet"),¹ although there's no evidence diuretics help swelling with a local cause, such as vein problems.⁵

Swelling from most causes may be helped by:

• raising your legs on a chair or pillows when you can²
• gentle exercise, such as walking, and not standing or sitting still for long periods²
• compression stockings or socks, the first-line treatment for venous insufficiency. Compression isn't safe if you have poor blood flow in the arteries of your legs (peripheral artery disease), so have your circulation checked first⁵
• wide, comfortable shoes and socks that aren't too tight²
• less salt in your diet¹
• an intermittent pneumatic compression pump (a sleeve that inflates around the leg) for some people.⁵

Treating swelling after an injury

For the first few days after a sprain, the first-aid steps known as RICE can help reduce swelling and pain:⁸ rest the injured area; apply ice for 20 minutes at a time, several times a day, never directly on the skin; use a compression bandage; and elevate the area above your heart while resting. Avoid heat in the early days, then start strengthening exercises once it begins to heal.⁸

When to seek medical help

Call triple zero (000) if you have swelling and you feel short of breath, have chest pain or tightness, cough up blood, or feel dizzy or faint. These can be signs of a blood clot in the lungs.²,¹⁰

See a doctor straight away, or go to an emergency department, if:¹,²,⁹

• the swelling came on suddenly, or is severe or painful
• only one foot, ankle or leg is swollen and there's no obvious cause, such as an injury
• the area is red or hot, or the redness is spreading
• you have a fever, or feel hot, cold or shivery
• you have diabetes and your feet or ankles are swollen.

If you're pregnant and swelling suddenly gets worse, contact your midwife, doctor or maternity hospital straight away.⁶

Otherwise, see your GP if swelling hasn't improved after a few days of self-care, is getting worse, or you have a heart, kidney or vein condition.² Our podiatrists can also help work out what's behind ongoing swelling and look after the skin and circulation of your feet.

If your feet or ankles are often swollen, book an appointment with our team at Foot Ankle Lower Limb.

References

1. Healthdirect Australia (2024). Fluid retention. https://www.healthdirect.gov.au/fluid-retention
2. NHS (2026). Swollen ankles, feet and legs (oedema). https://www.nhs.uk/conditions/oedema/
3. Healthdirect Australia (2024). Varicose veins. https://www.healthdirect.gov.au/varicose-veins
4. LeWine HE (2026). Why do my ankles swell in the summer? Harvard Health Publishing. https://www.health.harvard.edu/heart-health/why-do-my-ankles-swell-in-the-summer
5. Patel H, Skok C, DeMarco A (2022). Peripheral edema: evaluation and management in primary care. American Family Physician, 106(5), 557–564. https://www.aafp.org/pubs/afp/issues/2022/1100/peripheral-edema.html
6. NHS (2024). Swollen ankles, feet and fingers in pregnancy. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/swollen-ankles-feet-and-fingers/
7. Healthdirect Australia (2026). Pre-eclampsia. https://www.healthdirect.gov.au/pre-eclampsia
8. Healthdirect Australia (2024). Sprains and strains. https://www.healthdirect.gov.au/sprains-and-strains
9. Healthdirect Australia (2024). Cellulitis. https://www.healthdirect.gov.au/cellulitis
10. Healthdirect Australia (2025). Deep vein thrombosis (DVT). https://www.healthdirect.gov.au/deep-vein-thrombosis
11. Healthdirect Australia (2025). Lymphoedema. https://www.healthdirect.gov.au/lymphoedema

Reviewed by Andrew Schox, Podiatrist, BSc(Hons) PGradDipPod MPod. Last reviewed October 2026.