Quick answer: swollen ankles are most often caused by standing or sitting for long periods, heat, pregnancy, or certain medicines, and they usually settle with rest and elevation. Swelling in both legs that keeps coming back can signal heart, kidney, liver or vein problems, and swelling in one painful, warm leg can be a blood clot and needs same-day care.
First, sort it: one leg or both?
Both ankles swollen usually points to a body-wide cause: fluid retention from heat, salt, pregnancy, medicines, weak leg veins, or conditions affecting the heart, kidneys or liver.
One ankle or leg swollen usually points to a local problem: an injury, infection, or a blood clot (deep vein thrombosis, DVT).
Common, usually harmless causes
- Long periods of standing or sitting, such as long flights, desk jobs or shifts on your feet
- Hot weather, which makes blood vessels widen
- Too much salt, which makes the body hold water
- Pregnancy, especially in the third trimester (but sudden swelling of the face and hands needs checking)
- Extra weight
- Periods, with hormone-related water retention
- A minor sprain or injury
Medicines that can cause swelling
Some common medicines cause ankle swelling as a side effect:
- Calcium channel blockers for blood pressure, such as amlodipine
- Anti-inflammatory painkillers (ibuprofen, naproxen)
- Steroids
- Some diabetes medicines (pioglitazone)
- Estrogen or other hormone medicines
- Some antidepressants and nerve pain medicines
Don’t stop a prescribed medicine on your own. Tell your doctor or pharmacist, because there may be an alternative.
Medical causes to know about
- Chronic venous insufficiency: weak vein valves let blood pool in the legs. Swelling is worse by evening, may come with varicose veins, heaviness, and brownish skin changes.
- Heart failure: swelling in both legs together with breathlessness (especially lying flat), fatigue, and rapid weight gain
- Kidney disease: puffy ankles and puffy eyes in the morning, foamy urine. See our guide on early signs of chronic kidney disease.
- Liver disease: leg swelling with a swollen belly, yellow skin or easy bruising
- Underactive thyroid: puffy, firm swelling with tiredness and weight gain
- Lymphedema: persistent swelling after surgery, radiation or infection
- Blood clot (DVT): usually one leg, with pain, warmth and redness
- Infection (cellulitis): red, hot, tender skin, sometimes with fever
A quick check you can do
Press a finger firmly on the swollen area for about five seconds and let go. If a dent remains (pitting edema), that suggests fluid, and it is worth mentioning to a doctor, especially if it keeps recurring.
What helps at home
- Elevate your legs above heart level for 15 to 30 minutes, a few times a day
- Move: walk regularly, and flex your ankles and calves if you sit a lot
- Reduce salt and processed foods
- Wear supportive shoes, and avoid tight socks and garters
- Compression stockings can help with venous swelling, but ask a doctor first if you have diabetes, poor circulation or nerve problems
- Stay at a healthy weight
- Avoid prolonged standing where you can
If you have high blood pressure, our guide to lowering blood pressure naturally also covers salt and weight.
When to get urgent help
Call your emergency number or go to the emergency department if swelling comes with:
- Sudden shortness of breath, chest pain, or coughing up blood (possible clot in the lung)
- Fainting or severe dizziness
- Confusion
Get same-day medical care if:
- One leg is swollen, painful, warm, or red
- There is fever with red, hot swollen skin
- The skin is breaking down or you have a sore that won’t heal
When to book an appointment
See your doctor if swelling:
- Lasts more than a week or keeps returning
- Is getting worse
- Comes with fatigue, breathlessness, weight gain of a few pounds in a day or two, or less urine
- Occurs in someone with heart, kidney or liver disease
- Starts after you begin a new medicine
Your doctor may check your heart, kidneys, liver, thyroid and urine, and may arrange a vein ultrasound if a clot or vein problem is suspected.
Frequently asked questions
Why are my ankles swollen at night but fine in the morning?
Gravity pulls fluid down during the day, and lying flat lets it redistribute. This pattern is common with long standing, heat and mild vein weakness.
Are swollen ankles a sign of heart problems?
Sometimes, particularly if you also have breathlessness, fatigue, or swelling that is getting worse. Many cases are not heart-related.
Is swelling in pregnancy normal?
Mild swelling in the feet and ankles is common. Sudden swelling in the face or hands, severe headache or vision changes need urgent assessment.
Does drinking more water help?
Staying well hydrated is fine. Cutting water doesn’t reduce swelling, and cutting back on salt matters more.
Cura Editorial Team
Contributor at Cura Health Journal.