Long Covid: What is it and what are the symptoms?

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The Office for National Statistics (ONS) estimates about 1.3 million people in the UK have "long Covid" - symptoms lasting more than four weeks.

Most people who catch Covid don't become severely ill and get better relatively quickly.

But some have long-term problems after recovering from the original infection - even if they weren't very ill in the first place.

What are long Covid symptoms?

Long Covid is not fully understood, and there is no internationally-agreed definition - so measures of how common it is or what symptoms are involved vary.

According to the NHS website, these can include:

  • extreme tiredness
  • shortness of breath, heart palpitations, chest pain or tightness
  • problems with memory and concentration ("brain fog")
  • changes to taste and smell
  • joint pain

But patient surveys have identified tens and even hundreds of other symptoms. A large study by University College London (UCL) identified 200 symptoms affecting 10 organ systems.

These include hallucinations, insomnia, hearing and vision changes, short-term memory loss and speech and language issues. Others have reported gastro-intestinal and bladder problems, changes to periods and skin conditions.

The severity of symptoms varies, but many have been left unable to perform tasks like showering or remembering words. However these symptoms can have other causes too.

ONS research published in September 2021 found 0.5% of people who tested negative for coronavirus had at least one symptom that lasted for three months, compared to 3% who tested positive.

How will I know I have long Covid?

There is currently no standard test, with doctors first ruling out other possible causes for symptoms.

People who are suspected of having it are likely to be tested for other issues first like diabetes, thyroid function and iron deficiency, before being offered a long Covid diagnosis.

It is possible that a blood test could become available in the future.

What causes long Covid?

We don't yet know for sure.

It could be that the initial infection makes some people's immune systems go into overdrive, attacking not just the virus but their own tissues.

The virus itself getting into and damaging our cells might explain some symptoms like a loss of smell and taste, while damage to blood vessels could, for example, contribute to heart and lung problems.

Media caption,
It’s been more than a year, will I ever recover? - BBC reporter Lucy Adams explored long Covid in a Panorama film

Another theory suggests that fragments of the virus could remain in the body, possibly lying dormant and then becoming reactivated.

This happens with some other viruses, like herpes and the Epstein Barr virus which causes glandular fever.

However, there isn't currently much evidence for this happening with Covid.

It's likely there are several different things going on in different people, to cause such a wide range of problems.

Who gets long Covid and how common is it?

This is difficult to pin down because doctors only recently started recording long Covid.

The latest ONS estimate suggests that about 1.3 million people in the UK have it. Of those, 892,000 (70%) first caught the virus at least 12 weeks ago and 506,000 (40%) at least a year ago.

The survey asked nearly 352,000 people to record their own symptoms.

It suggests the condition is most common in:

  • 35- to 69-year-olds
  • women
  • people with underlying conditions that limit their day-today activities
  • those working in health and social care
  • people living in poorer areas

But in September, it suggested this proportion was one in 40.

Figures will continue to change as more data is collected, and will vary according to the definitions used.

What about children?

Children are less likely than adults to catch Covid and are therefore less likely to develop long Covid - but some still do.

However, in August 2021 leading experts said they were reassured about the scale of long Covid in young people after the biggest study in the world showed persistent symptoms were less common than feared.

Some early estimates had suggested as many as half of all children who caught coronavirus would develop long Covid.

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A team of researchers, led by the Great Ormond Street Institute of Child Health, investigated more than 200,000 positive cases among 11 to 17-year-olds between September 2019 and March 2020.

They think that between 4,000 and 32,000 of those were still experiencing symptoms 15 weeks later.

We don't have know how severe the symptoms were, but there was little evidence that children were left bedridden or unable to go to school.

But the researchers stressed the risk to young people is "not trivial", and said it was vital children get the medical support they need.

Can the vaccine help?

Vaccination can help prevent people contracting the virus and developing long Covid in the first place.

It may also prevent infections "turning into" long Covid but this is less clear.

Image source, Getty Images

What treatments are available?

About 90 long Covid assessment centres have been set up across England.

Similar clinics have opened in Northern Ireland, while in Scotland and Wales patients are referred to different services by their GPs or other health professionals, depending on their symptoms.

At the moment there are no proven drug treatments and the main focus is on managing symptoms and gradually increasing activity.