How does Covid-19 affect your heart? (2025)

What's on this page

• What’s the link between Covid-19 and heart attacks and stroke?

• How does Covid-19 affect the heart?

• What heart and circulatory conditions can you get after Covid-19?

  • Covid-19 and blood clots

  • Covid-19 and heart damage

  • Covid-19 and heart palpitations or high heart rate

  • Covid-19 and myocarditis

• Can Covid-19 cause high blood pressure?

• Can Covid-19 cause diabetes?

What’s the link between Covid-19 and heart attacks and stroke?

Research suggests that Covid-19 can increase the risk of heart and circulatory conditions, like heart attackand stroke, after infection.

A study published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology in October 2024 used data from over 11,000 people, with and without existing heart or circulatory conditions, who tested positively for Covid-19 between February and December 2020. This was before the Covid-19 vaccine was available in the UK.

Compared to nearly 220,000 uninfected people, those infected with Covid-19 were more than twice as likely to have had a heart attack or stroke or died from any cause by October 2022.

For people who were hospitalised with Covid-19, the risk of these events was 4 times higher than for those who did not test positive for the virus.

How does Covid-19 affect the heart?

It’s thought that Covid-19 may damage the endothelium (the inner lining of blood vessels in the body).

This damage can lead to abnormal blood clotting, ‘leaky’ blood vessels and reduced blood flow.

This could be part of the reason why people with existing heart and circulatory conditions are at a higher risk of complications from Covid-19.

What other conditions can you get after Covid-19?

Covid-19 and blood clots

People who develop severe illness from Covid-19 are at a higher risk of blood clots.

This is thought to be due to damage to the blood vessels, either directly caused by the virus or because of the immune system’s response to the infection.

Depending on where they are in your body, blood clots can cause serious problems.

If a blood clot forms in the blood vessels supplying blood to your heart (coronary arteries), they can block the blood supply, causing aheart attack.

And clots that block the blood supply to the brain can cause astroke.

Blood clots can also cause deep vein thrombosisin the blood vessels in your leg, or a pulmonary embolism if they form in the blood vessels in the lung.

Covid-19 and heart damage

Covid-19 can cause fever and inflammation, which places extra stress on the heart as your body fights the infection.

And if the Covid-19 infection is severe enough to damage the lungs, or a blood clot forms in the lungs’ blood vessels, this can reduce the amount of oxygen and nutrients reaching the heart.

This increased demand on the heart, paired with a lack of oxygen, can cause damage to the heart muscle.

In some severe cases, this could lead to heart failure, which is when the heart is not pumping blood around the body as well as it should.

Research published in 2022 in the journal Nature Medicine suggested that people who have had Covid-19 may be more likely to be diagnosed with heart failure.

The study found almost 154,000 people in the United States who tested positive for Covid-19 between March 2020 and January 2021 were 72 per cent more likely to have heart failure a year after they were infected, compared to people who did not have the virus.

Speak to your doctor if you experience fainting, feeling lightheaded or tired, or if you have a new persistent cough, shortness of breath or swelling in your feet and ankles. These are all symptoms of heart failure.

Covid-19 and heart palpitations or high heart rate

When you have Covid-19, your heart needs to work harder to pump more blood around your body to fight the infection. This can lead to heart palpitationsor a high or irregular heart rate.

Heart palpitations are when you become more aware of your heartbeat – this can feel like a fluttering or pounding sensation in your chest.

They’re not usually a cause for concern, but it’s a good idea to go to your doctor if you're worried about them, they last a long time, do not improve or get worse, or you have a history of heart problems.

Changes to your heart rate can also happen for other common reasons, including dehydration, anxiety, medicines and other health conditions.

Some people also experience changes to their heart rate after they have recovered from Covid-19.

It’s thought this could be due to the effect of Covid-19 and the body's immune system on the autonomic nervous system, which regulates essential body processes, like blood pressure, heart rate and breathing.

Speak to your doctor if your heart rate is irregular, frequently high or if you have any symptoms such as dizziness or fainting, as this could be a sign of an abnormal heart rhythm (arrhythmia).

• Learn more about your heart rate.

Covid-19 and myocarditis

Covid-19 can also lead to inflammation of the heart muscle (myocarditis) and heart lining (pericarditis).

A review published in the Canadian Journal of Cardiology in December 2022 of 4 studies with data from 20 million people found people who had Covid-19 were 5 times more likely to have myocarditis over the following year than those who did not have the virus.

Earlier in the pandemic, scientists thought that myocarditis may be caused by the virus attacking the heart muscle cells directly.

But many researchers now think this damage to the heart can be the result of the immune system overreacting to the infection.

Myocarditis and pericarditis can also be caused by other viral infections, not just Covid-19.

Speak to your GP if you experience chest pain or discomfort, shortness of breath or heart palpitations.

While many cases of myocarditis are mild and have no lasting effects, in severe cases it can scar the heart muscle, so it’s important to get treatment as early as possible.

• Read about myocarditis and Covid-19 vaccines.

Can Covid-19 cause high blood pressure?

Some research suggests that Covid-19 could be linked to an increased risk of developing high blood pressure(hypertension).

This is a serious condition, as high blood pressure raises your chances of having a heart attack or stroke.

A United States study published in the journal Hypertension in August 2023 compared data from just over 45,000 people infected with Covid-19 to nearly 14,000 people infected with flu (influenza) to see how many in each group developed high blood pressure.

The researchers found those hospitalised with Covid-19 were twice as likely to be diagnosed with persistent high blood pressure over the following 6 months than those hospitalised with flu.

And those who had Covid-19, but were not hospitalised, were 1.5 times more likely to develop persistent high blood pressure than those with flu who did not go to hospital.

Overall, 1 in 5 people hospitalised with Covid-19 went on to develop persistent high blood pressure – which was diagnosed if participants had a systolic blood pressure above 140 mmHg or a diastolic blood pressure above 90 mmHg.

However, this study does not prove Covid-19 directly causes high blood pressure, as there may be other reasons for this link.

For example, people with Covid-19 may have been more likely to return to their doctor for follow-up tests than those with flu, and therefore had a higher chance of being diagnosed with high blood pressure.

High blood pressure can often be symptomless, so it’s important to get yours regularly checked whether you’ve recently had Covid-19 or not.

Can Covid-19 cause diabetes?

There is some evidence of a link between Covid-19 and an increased risk of developing diabetesin the weeks after infection.

Diabetes is a condition where your body does not produce enough of the hormone insulin, or cannot use the insulin it does make, which can raise levels of glucose (a type of sugar) in your blood.

In July 2022, a UK study in PLOS Medicine found the risk of diabetes was 81 per cent higher in the 4 weeks after a Covid-19 infection. But this fell back to pre-Covid risk levels in the 5 to 6 months following infection.

The study, by researchers at King’s College London, compared the health records of almost 429,000 people with Covid-19 to the same number of people of the same age and gender who had not tested positive. None had diabetes before the study.

Some studies have suggested this increased risk of diabetes is because Covid-19 can damage the body's ability to produce insulin.

A small study published in November 2024 in the journal Cell Stem Cell compared 7 tissue samples of an organ called the pancreas from people who had died from Covid-19 to 8 samples from people who had died of other causes.

The researchers found that the parts of the pancreas that produce insulin were more damaged in the samples from people who had died from Covid-19 than in those who had not.

On further analysis, they found the cells that produce insulin may have been damaged by the body’s immune response to Covid-19 in those who had died from the virus.

However, we do not know if other factors affected the pancreas in people who died from Covid-19.

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