Swollen ankles and legs

What swollen ankles and legs actually are

Swelling in the legs, also known as oedema, happens when fluid builds up in the tissues. In simple terms, fluid may leak out of blood vessels or may not be cleared effectively by the body. Gravity plays a part too, which is why swelling so often shows up in the lower legs, the ankles and the feet.

The description people give in clinic is fairly consistent. Shoes start to feel tighter, socks leave deeper marks on the skin, and the swelling is at its worst towards the end of the day.

That much on its own tells you very little about the cause. The pattern is what matters, and four things about the pattern are worth noticing before you see anyone.

• Whether one leg is swollen or both
• Whether it came on over hours, over days or over months
• Whether it settles after a night of rest or is still there in the morning
• Whether your breathing, your energy or your weight has changed at the same time

The common causes that are not the heart

Not all swollen legs are caused by heart problems, and most are not. Prolonged standing, warm weather and minor circulation changes are all benign causes, and swelling from these is usually temporary.

Several medical causes are also more common than a cardiac one.

One pattern is the exception to all of this. Swelling that affects only one leg, particularly if it appears suddenly, may suggest a different cause such as a blood clot. That needs urgent same day medical assessment rather than a routine appointment, so get advice straight away instead of waiting to see whether it settles. If it comes with chest pain or breathlessness, do not wait for advice at all. Call 999.

This is why the pattern of swelling is so important in working out the underlying cause. Swelling that is present in both legs and builds slowly raises a different set of questions from swelling that appears in one leg overnight.

• Varicose veins or venous insufficiency
• Kidney problems
• Liver conditions
• Certain medications
• Lymphatic system disorders

When the swelling may be coming from the heart

The heart plays a central role in circulating blood around the body. When it is not pumping efficiently, blood can back up in the veins, pressure rises and fluid leaks into the surrounding tissues. This is most commonly seen in heart failure, which does not mean the heart has stopped working, only that it has become less efficient at pumping.

Swollen legs related to the heart often develop gradually. The swelling is usually present in both legs and tends to worsen towards the end of the day. Swelling in the legs, ankles or abdomen is also listed among the symptoms of cardiomyopathy, which affects the heart muscle itself, and of ventricular hypertrophy, where the muscle of a pumping chamber thickens. It can sit alongside a heart murmur where a valve is narrowed or leaking.

What makes a cardiac cause more likely is rarely the swelling on its own. It is the company it keeps.

None of these symptoms are unique to the heart, and each of them can occur with other conditions. That is the argument for an assessment rather than a guess, in either direction.

• Shortness of breath, particularly when walking or lying flat
• Waking at night feeling breathless
• Fatigue or reduced energy levels
• Weight gain due to fluid retention
• A gradual drop in how much you can do before you have to stop

What Dr Jogiya would do about it

Assessment starts with the full clinical picture rather than with a test. Dr Jogiya will usually ask when the swelling started, whether it affects one leg or both, whether it changes through the day, and whether anything else has come with it such as breathlessness or fatigue.

From there he will usually arrange an echocardiogram, an ultrasound scan that shows how strongly the heart muscle is pumping and how the valves are working. It is the single most useful test for investigating suspected heart failure, valve disease and structural causes of breathlessness. Blood tests typically include NT-proBNP, a marker of heart strain that can be very helpful in confirming or ruling out heart failure, alongside kidney, liver and thyroid function.

It is rarely one test that provides the answer. It is the combination of history, examination and investigations that allows the cause to be identified.

• A 12 lead ECG, which records the electrical activity of the heart and can pick up rhythm problems or signs of strain
• An echocardiogram, to assess how strongly the heart is pumping and how the valves are working
• Blood tests, including NT-proBNP and kidney, liver and thyroid function
• A chest X ray, to look for fluid on the lungs or an enlarged heart
• Ultrasound scans of the legs, if a clot is suspected
• A cardiac MRI or an ECG monitor, where the first results raise further questions

What may help while you wait to be seen

If the swelling is mild, a few simple steps may help.

These measures can reduce mild swelling, but they are not a substitute for being assessed and they will not address an underlying cause if there is one. Do not use them to wait out swelling that is new, one sided, getting worse, or coming with breathlessness or fatigue, and do not stop or change any prescribed medication on the strength of them.

• Elevate your legs when resting
• Stay physically active to support circulation
• Avoid sitting or standing in one position for long periods
• Reduce excessive salt intake
• Stay well hydrated

When to book an appointment rather than wait

One of the most common scenarios in clinic is people assuming that swollen legs are simply due to age or to standing for long periods. In many cases that is true. What tends to happen otherwise is that gradual swelling linked to heart function goes unnoticed for some time. People adapt, they reduce their activity or change their footwear, and by the time breathlessness appears the condition may already be more advanced.

It is worth seeking medical advice if swollen legs do any of the following.

Early evaluation often provides reassurance when the cause is benign. When the heart is involved, it also allows treatment to begin sooner. Dr Jogiya sees private patients at clinics across Kingston upon Thames and central London, in person and virtually. This page is general information rather than individual medical advice, so please speak to your GP or a cardiologist about your own symptoms.

• Persist or worsen over time
• Affect both legs and are associated with breathlessness
• Are accompanied by fatigue or reduced exercise tolerance
• Develop suddenly, particularly in one leg, which needs urgent same day assessment rather than a routine booking
• Cause discomfort or skin changes