Swollen Legs and Ankles: Could It Be a Heart Problem?
Persistent swelling in the feet, ankles or lower legs can be caused by many conditions. In some patients, it may reflect heart failure, valve disease, pulmonary hypertension or reduced pumping efficiency. In others, the cause may be venous insufficiency, DVT, lymphoedema, kidney disease, liver disease or medication-related fluid retention.
Can swollen legs and ankles be caused by the heart?
Yes, swollen legs and ankles can sometimes be related to a heart problem, especially heart failure or right-sided heart strain. When the heart does not pump efficiently, blood can back up in the veins and fluid can leak into the lower-limb tissues, causing peripheral oedema. However, swelling is not always cardiac. Common alternatives include venous insufficiency, varicose veins, DVT, lymphoedema, kidney disease, liver disease, pregnancy, being overweight and medication side effects.
An echocardiogram may be important when swollen ankles occur with breathlessness, fatigue, reduced exercise tolerance, palpitations, chest discomfort, abnormal ECG findings, a heart murmur, high blood pressure or cardiovascular risk factors.
What is leg and ankle swelling?
Leg swelling occurs when excess fluid accumulates within the tissues of the lower limbs. The medical term is oedema. It may affect one leg, both legs, the ankles only, the feet, the calves or the whole lower limb.
Swelling may appear suddenly or develop gradually. It may feel heavy, tight or uncomfortable. In pitting oedema, pressing a finger into the swollen area leaves a temporary indentation.
Fluid balance depends on blood vessel pressure, protein levels in the blood, kidney function, hormonal regulation and lymphatic drainage. Swelling develops when this balance is disrupted.
When swelling may need urgent attention
Seek urgent medical help if swelling is sudden, severe, one-sided, painful, red, warm, associated with chest pain, shortness of breath, coughing blood, collapse, facial drooping, weakness on one side or difficulty speaking.
This may indicate DVT, pulmonary embolism, severe heart failure, stroke or another emergency.
7 important heart and circulation causes of swollen legs and ankles
| Possible cause | Why swelling happens | Useful investigation |
|---|---|---|
| 1. Heart failure | The heart may not pump efficiently, causing venous congestion and fluid retention. | Echocardiogram, ECG, blood tests and cardiology review. |
| 2. Right-sided heart strain | Blood backs up in the venous system, causing ankle swelling and sometimes abdominal fluid. | Echo to assess right-heart size and function. |
| 3. Pulmonary hypertension | High pressure in lung arteries increases right-heart workload and venous congestion. | Echo with estimated pulmonary pressure and cardiology pathway. |
| 4. Heart valve disease | Leaking or narrowed valves can overload the heart and contribute to fluid retention. | Echo is the key non-invasive test for valve function. |
| 5. Cardiomyopathy | Heart muscle disease may reduce pumping efficiency and increase venous pressure. | Echo, ECG and specialist review. |
| 6. Venous insufficiency | Leg vein valves fail, blood pools in the lower legs and ankles swell. | Venous insufficiency Doppler scan. |
| 7. Deep vein thrombosis | A clot blocks deep venous flow, often causing one-sided swelling, pain, warmth or redness. | DVT Doppler ultrasound scan and urgent medical assessment. |
Why does heart disease cause ankle swelling?
The heart acts as the body’s central pump. When the heart becomes weakened, stiff or overloaded, blood returning to the heart may back up in the veins. As venous pressure rises, fluid can leak from blood vessels into surrounding tissues. Because gravity pulls fluid downwards, this often appears first in the feet, ankles and lower legs.
In heart failure, the body also activates hormonal systems that retain salt and water. Although these systems are initially designed to protect blood pressure and circulation, long-term activation can increase fluid volume and worsen swelling.
What an echocardiogram can show
- Reduced pumping function or heart failure features
- Diastolic dysfunction, where the heart is stiff and does not relax well
- Heart valve narrowing or leakage
- Right-heart enlargement or dysfunction
- Estimated pulmonary pressures
- Cardiomyopathy and chamber enlargement
- Fluid around the heart in selected cases
Heart failure and swollen ankles
Heart failure does not mean the heart has stopped. It means the heart is not pumping blood efficiently enough to meet the body’s needs. Swollen ankles may occur alongside breathlessness, fatigue, reduced exercise tolerance, difficulty lying flat, night-time breathlessness or rapid weight gain from fluid retention.
Right-sided heart failure is particularly associated with leg swelling, because blood returning from the body backs up in the veins. Left-sided heart failure more commonly causes breathlessness and fluid in the lungs, but both sides of the heart are closely connected.
Pulmonary hypertension, valves and cardiomyopathy
Pulmonary hypertension can place extra strain on the right side of the heart and may cause leg swelling, breathlessness, fatigue or dizziness. Valve disease can also increase cardiac workload and eventually lead to fluid retention. Cardiomyopathy can reduce pumping efficiency and raise venous pressure.
These are some of the reasons an echocardiogram is valuable when swelling is persistent, unexplained or linked with cardiac symptoms.
Non-cardiac causes that must also be considered
Venous insufficiency
Often causes heavy legs, varicose veins, aching, ankle swelling and skin changes. Symptoms are usually worse after standing and improve with elevation.
View venous insufficiency scanDeep vein thrombosis
DVT can cause one-sided swelling, calf pain, redness, warmth and tenderness. This requires urgent assessment because of pulmonary embolism risk.
View DVT Doppler scanLymphoedema
Impaired lymphatic drainage can cause persistent swelling, often involving the foot and toes, sometimes with thickened skin.
Kidney disease
Reduced kidney function may cause salt and water retention, swollen ankles, facial puffiness, fatigue and changes in urination.
Liver disease
Reduced albumin production can allow fluid to leak into tissues, causing swollen legs and sometimes abdominal fluid.
View abdominal ultrasoundMedication side effects
Calcium-channel blockers, steroids, hormone therapy, anti-inflammatory medicines and some diabetes medications can contribute to swelling.
When should someone with swollen ankles consider an echocardiogram?
An echocardiogram may be appropriate if swelling is persistent or unexplained, particularly when it occurs with cardiovascular symptoms or risk factors.
Symptoms that may suggest heart involvement
- Breathlessness or reduced exercise tolerance
- Difficulty lying flat or waking breathless at night
- Fatigue or rapid weight gain
- Palpitations or abnormal pulse
- Chest discomfort
- Known heart murmur or abnormal ECG
Risk factors that increase concern
- High blood pressure
- Diabetes
- High cholesterol
- Smoking history
- Previous heart attack or coronary artery disease
- Family history of heart disease or stroke
Related heart and vascular services
London Private Ultrasound provides joined-up heart and vascular assessment pathways in Central London and St Albans. The right test depends on your symptoms, risk factors and clinical background.
Private Echocardiogram
Heart ultrasound for pumping function, valves, chamber size, diastolic function and right-heart assessment.
Heart Health Check
Cardiologist-led assessment with echocardiogram, 12-lead ECG, physical examination and same-day verbal findings.
Private Cardiology Clinic
A joined-up pathway for cardiology consultation, ECG, Echo and monitoring where appropriate.
DVT Doppler Ultrasound
Urgent Doppler assessment for suspected deep vein thrombosis, particularly with one-sided swelling or calf pain.
Venous Insufficiency Doppler
Vein reflux mapping for varicose veins, heavy legs, aching, skin changes and long-standing ankle swelling.
Carotid Doppler Ultrasound
Neck artery ultrasound to assess plaque, narrowing and stroke-risk markers in patients with vascular risk factors.
Heart Health & Stroke Risk Screening
A broader cardiovascular screening pathway combining heart rhythm and vascular assessment.
AAA Ultrasound Scan
Abdominal aorta ultrasound for aneurysm screening in selected vascular-risk patients.
Which LondonSono heart package may be suitable?
| Package | Best for | Link |
|---|---|---|
| Heart Health Check — £449 | Core cardiac assessment with cardiologist consultation, echocardiogram, ECG and physical examination. | View Heart Health Check |
| Heart Health Check Plus — £685 | Cardiac assessment plus GP consultation and advanced blood tests for metabolic and cardiovascular risk. | View Plus package |
| Heart Health Check Premium — £995 | Plus package with carotid Doppler ultrasound for additional vascular and stroke-risk information. | View Premium package |
| Heart Health Check Diamond — £1,220 | Most comprehensive package, adding carotid Doppler and AAA ultrasound to cardiac assessment. | View Diamond package |
Frequently asked questions
Can swollen ankles be a sign of heart failure?
Yes. Swollen ankles can occur when the heart is not pumping efficiently and fluid builds up in the lower limbs. However, many non-cardiac causes are also possible, including venous insufficiency, medications, kidney disease, liver disease and lymphoedema.
When should leg swelling be checked urgently?
Urgent medical assessment is needed if swelling is sudden, painful, one-sided, associated with chest pain, shortness of breath, coughing blood, collapse, or symptoms suggestive of DVT, pulmonary embolism, stroke or severe heart failure.
How can an echocardiogram help with swollen legs?
An echocardiogram can assess heart pumping function, chamber size, valve disease, right-heart strain, pulmonary pressure estimates and diastolic function. These findings can help determine whether heart disease may be contributing to fluid retention.
Is leg swelling always caused by the heart?
No. Common non-cardiac causes include varicose veins, chronic venous insufficiency, DVT, lymphoedema, kidney disease, liver disease, pregnancy, being overweight and medication side effects.
What scan is best for one swollen leg?
One-sided swelling, especially with calf pain, redness, warmth or tenderness, may require urgent DVT assessment. A DVT Doppler ultrasound is commonly used to assess the deep veins of the leg.
What scan is useful for varicose veins and heavy swollen legs?
A venous insufficiency Doppler scan maps leg veins and valves to identify reflux, which can cause varicose veins, heavy legs, aching and chronic ankle swelling.
Do I need a GP referral to book privately?
Many London Private Ultrasound heart and vascular services can be booked directly without a GP referral, depending on the service and clinical suitability.
Can kidney or liver problems cause swollen ankles?
Yes. Kidney disease can cause salt and water retention, while liver disease may reduce blood protein levels and allow fluid to leak into tissues. Blood tests, urine tests and abdominal imaging may be needed depending on symptoms.
Trusted medical references
This section provides outbound links to authoritative external medical resources. These links are included as standard followed outbound links, not nofollow links.
- NICE NG106 – Chronic heart failure in adults
- NHS – Swollen ankles, feet and legs (oedema)
- British Heart Foundation – Heart failure
- British Heart Foundation – Swollen ankles and feet
- NHS – Pulmonary hypertension
- NHS – Lymphoedema
- World Health Organization – Cardiovascular diseases
- American Heart Association – Warning signs of heart failure
Persistent swelling should not be ignored
Swollen legs and ankles are often harmless or related to veins, medication, posture or lifestyle. However, persistent, progressive or unexplained swelling can sometimes be an important sign of heart failure, valve disease, pulmonary hypertension, cardiomyopathy or DVT.
An echocardiogram can help assess whether the heart may be contributing to swelling, while vascular Doppler scans can assess leg veins, DVT risk and broader vascular disease.
Book the right assessment
For heart-related symptoms, start with a private echocardiogram or cardiologist-led heart health check. For one-sided leg swelling or suspected vein problems, DVT or venous Doppler may be more appropriate.
Article preparation and clinical review
This patient information page was prepared with AI-assisted editorial support and reviewed for clinical accuracy by:
Dr Pedram Aghaei — Vascular Scientist, SVT reg. SVT 679 · Registered Clinical Technologist, RCT reg. 93290 · BMUS: 20702
Dr Hosna Rashidi — BMUS 29386 · SVT reg: 1756
This article is intended for general patient information only and does not replace a medical consultation. If you experience sudden severe leg swelling, chest pain, shortness of breath, coughing up blood, collapse, or symptoms suggestive of a deep vein thrombosis, pulmonary embolism, heart failure, stroke, heart attack or another medical emergency, please seek urgent medical attention immediately or contact emergency services.