Swollen Ankles and Leg Swelling
Swollen Ankles and Leg Swelling: A Complete Patient Guide
Swollen ankles and legs (peripheral oedema) happen when fluid collects in the tissues of the feet, ankles and lower legs. It is very common, and often harmless, for example after a long day on your feet or a long flight, in hot weather or in pregnancy. However, persistent or new swelling can be a sign of a medical problem, including heart, kidney, liver, vein or thyroid disease, or a side effect of medicines.
From a heart point of view, swollen ankles are one of the typical signs of heart failure, in which the heart cannot pump blood efficiently so that fluid backs up in the veins and leaks into the tissues. Swelling of both legs, which leaves a dent when pressed (“pitting”), worse by the end of the day, and accompanied by breathlessness or tiredness, should always be checked.
By contrast, swelling of one leg only, particularly if painful, red or warm, may be a blood clot (deep vein thrombosis), which is an urgent problem. Identifying the cause matters because the treatment differs completely: leg swelling from heart failure needs heart treatment, vein problems need compression, and medicine-related swelling needs a medication review.
The pattern of swelling points to its cause.
What the pattern of swelling can tell you
What swollen ankles look and feel like
Puffiness around the ankles and feet, with socks or shoes leaving marks
Skin that looks tight, shiny or stretched, and that pits when pressed with a finger
Swelling that is worse in the evening and better after a night’s rest with the legs raised
Heaviness or aching in the legs, or weight gain over days
Heart-related clues
Both legs affected, spreading up the legs or into the abdomen
Breathlessness, needing extra pillows, tiredness, or reduced stamina
Weight gain of more than about 2 kg over a few days
Other clues
One leg only, painful or red: possible deep vein thrombosis
Swelling with puffiness around the eyes and frothy urine: kidney disease
Yellow skin, abdominal swelling or easy bruising: liver disease
Brown skin changes, varicose veins or ulcers: chronic venous insufficiency
Swollen ankles have many causes, and the most common ones are not serious.
How fluid builds up in the legs
Heart and circulation causes
Chronic venous insufficiency (weak vein valves) and varicose veins
Deep vein thrombosis, usually one-sided
Pulmonary hypertension, pericardial constriction and severe valve disease
Medicines
Calcium channel blockers (especially amlodipine and nifedipine)
Anti-inflammatory painkillers (ibuprofen, naproxen), steroids, pioglitazone, some antidepressants, gabapentin and pregabalin, and hormones
Other medical causes
Kidney disease, nephrotic syndrome and low blood protein (albumin)
Liver disease (cirrhosis) and an underactive thyroid
Lymphoedema, pregnancy, obesity and the menstrual cycle
Everyday causes
Standing or sitting for long periods, hot weather, long flights, a salty meal and being overweight can all cause temporary swelling.
Diagnosis starts with examination and a few simple tests, and the aim is to find or exclude a heart cause.
How the cause is found
1. History and examination
Your cardiologist will ask about duration, one or both legs, breathlessness, medicines, past illnesses and weight change, and check pulses, blood pressure, heart sounds, the neck veins, lungs, abdomen and skin. They will look for pitting and signs of venous disease.
2. ECG and blood tests
An ECG checks the rhythm and signs of heart strain. Blood tests include NT-proBNP (a marker of heart strain), kidney and liver function, albumin, thyroid function, blood count and glucose. A urine test checks for protein.
3. Echocardiogram
An echocardiogram assesses heart function, valves, right heart pressures and the pericardium, and is the key test if a heart cause is suspected.
4. Leg vein tests
A leg ultrasound (duplex) looks for clots or venous reflux. A D-dimer blood test and clinical score are used when DVT is suspected.
5. Further tests
Depending on findings, a chest X-ray, abdominal ultrasound, cardiac MRI or other tests may be needed to look for kidney, liver or lymphatic causes.
Treatment depends on the cause, so avoid diuretics (“water tablets”) or compression unless advised after the cause is known.
If it is the heart
Treatment of heart failure: foundational medicines, a diuretic to remove fluid, a low-salt diet and daily weights. Treating valve disease, rhythm problems and high blood pressure also helps.
If it is the veins
Graduated compression stockings (after arterial disease and heart failure have been excluded)
Leg elevation, regular walking and calf exercises
Treatment of varicose veins or venous ulcers by a vascular team where needed
If it is a clot
An anticoagulant is started promptly. Deep vein thrombosis needs urgent same-day assessment.
If it is a medicine
Your doctor may reduce the dose, change to an alternative or add a medicine. Do not stop prescribed medicines without advice.
If it is kidney, liver or thyroid disease
Treating the underlying condition is the key, with specialist care.
Elevate your legs when sitting, ideally above hip level for 30 minutes several times a day.
Keep moving. Walk regularly and avoid long periods of sitting or standing still. Calf and ankle exercises help circulation.
Reduce salt and avoid highly processed food.
Maintain a healthy weight and wear comfortable, supportive footwear.
Weigh yourself regularly if you have heart failure.
Look after your skin with moisturiser and prompt treatment of any cracks or infections.
Do not use compression stockings or water tablets without medical advice, as they may be unsuitable.
Support is available from the British Heart Foundation and the NHS.
The outlook depends on the cause. Swelling from everyday causes or medicines usually resolves completely.
Swelling from heart failure improves greatly with modern treatment, and fluid can often be controlled for long periods.
Venous swelling is a long-term issue but can be managed well with compression, exercise and skin care.
A blood clot needs prompt treatment to prevent complications, after which most people do well.
Persistent unexplained swelling should not be ignored.
Persistent or new swelling of the ankles should be assessed, particularly if both legs are affected.
What to do about swollen ankles
Arrange an assessment if you have:
Swelling that has lasted more than a few days or is getting worse
Swelling of both legs with breathlessness, tiredness or weight gain
Swelling after starting a new medicine
A history of heart, kidney or liver disease with new swelling
Swelling with skin changes, ulcers or recurrent infections
Usually harmless if:
It is mild, equal in both legs, appears after prolonged standing or heat, settles overnight and is not associated with breathlessness or other symptoms.
These features need prompt medical assessment, ideally the same day.
Red flags
Swelling in one leg only, especially with pain, warmth or redness
Swelling with breathlessness or needing to sit up to breathe
Rapid weight gain (more than about 2 kg in 3 days)
A hot, red, painful leg with fever (possible infection or cellulitis)
Swelling with reduced urine output, yellow skin or abdominal swelling
What to do
Seek same-day assessment. A leg ultrasound and blood tests can quickly identify a clot or heart problem.
Swelling with the following needs emergency help.
Call 999 immediately if you have swollen legs with:
Sudden severe breathlessness, or chest pain
Coughing up blood or pink frothy phlegm
Fainting or collapse
A rapid heartbeat with feeling very unwell
Why this matters
These features could mean a clot has reached the lungs (pulmonary embolism) or severe heart failure, both of which are emergencies.
Swollen ankles are caused by fluid in the tissues, and are often harmless.
Persistent swelling of both legs with breathlessness or tiredness may indicate heart failure.
One-sided painful swelling may be a blood clot, which needs same-day assessment.
Other causes include vein disease, kidney, liver and thyroid problems and medicines.
Common medicine causes are amlodipine, anti-inflammatories, steroids and pioglitazone.
Key tests are an ECG, NT-proBNP, blood and urine tests, echocardiogram and leg ultrasound.
Treatment depends on the cause: avoid self-treating with water tablets.
Elevation, walking and reduced salt help many causes.
Guidelines and sources
This page follows current UK and European guidance:
NICE NG106: Chronic heart failure in adults: diagnosis and management.
McDonagh TA et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. European Heart Journal 2021;42:3599-3726.
These are the questions patients most often ask about swollen ankles.
What causes swollen ankles?
Prolonged standing, heat, pregnancy and weight are everyday causes. Medical causes include heart failure, vein disease, blood clots, kidney, liver or thyroid disease, and medicines such as amlodipine.
Can swollen ankles be a sign of heart failure?
Yes, particularly if both legs are affected, the swelling pits, and you are also breathless or tired. See our heart failure guide.
When should I worry about swollen ankles?
If it persists for more than a few days, affects both legs with breathlessness, is rapid or painful, or involves one leg only. Call 999 for chest pain or sudden severe breathlessness.
Why are my ankles swollen at the end of the day?
Gravity pulls fluid down when you sit or stand for long periods. If it settles overnight and you have no other symptoms, it is usually benign, though persistent evening swelling is worth checking.
Can blood pressure tablets cause swollen ankles?
Yes, especially calcium channel blockers such as amlodipine and nifedipine. Do not stop them, but ask your doctor, who may lower the dose or change the medicine.
What tests are done for swollen ankles?
An examination, an ECG, blood tests (including NT-proBNP, kidney, liver and thyroid), a urine test, an echocardiogram, and a leg ultrasound if a clot is suspected.
Should I take water tablets for swollen ankles?
Not without advice. Water tablets help swelling due to heart failure but can harm kidneys and cause problems if the cause is vein disease or medicines.
Do compression stockings help?
For vein-related swelling, yes, once heart failure and arterial disease are excluded. They can be harmful in some conditions, so seek advice first.
Can I have a private assessment for swollen ankles?
Yes. A telephone, video or face-to-face consultation in Peterborough or Corby can assess your swelling, with ECG reporting and echocardiography arranged to check for a heart cause.
- Is my swelling due to my heart?
- Which tests do I need?
- Could a medicine be causing it?
- Do I need a water tablet, and for how long?
- Are compression stockings safe for me?
- How much salt and fluid is right for me?
- What symptoms mean I should seek urgent help?
- Do I need blood tests to check my kidneys, liver, thyroid and protein levels?
- Could a blood clot or vein problem be the cause, and do I need a leg scan?
- Would raising my legs, moving more or losing weight help?
Where the fluid comes from
Heart failure: the heart pumps less effectively, pressure rises in the veins, and fluid leaks into the legs.
Vein disease: weak valves allow blood to pool in the legs.
Kidney or liver disease: sodium retention and low albumin let fluid escape from vessels.
Medicines: some widen the small vessels of the legs, so fluid leaks out.
Blood clot: a clot blocks the vein, causing painful, one-sided swelling.
Where the fluid comes from
Checking for a dent
Looking after swollen legs
If you have swollen ankles or legs, breathlessness or sudden weight gain, you may benefit from a telephone consultation or video consultation to discuss your symptoms in detail, or a face-to-face consultation in Peterborough or Corby for a more comprehensive assessment.
Investigations such as ECG and echocardiography may be recommended to look for a heart cause.
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Medically reviewed by Dr Salam Salloum, Consultant Cardiologist. Last updated: . This page is for general information and does not replace personal medical advice.