Millions of people around the world have suffered lingering symptoms after a Covid-19 infection, but the science in the field is still emerging.
Researchers are scrabbling to find answers to the many unknowns around long Covid.
Experts are examining how the condition affects different people, finding out who is most at risk and looking for potential treatments.
Here are your questions answered about what we know so far.
– What is long Covid?
Long Covid, post-Covid-19 condition, post-Covid syndrome and Covid long haulers are all different names and labels for the same phenomenon – symptoms which persist after a Covid infection.
People will experience long Covid differently; some may have had a mild initial infection and then felt a different array of symptoms for months or even years afterwards, while others could be severely ill in hospital and then experience a different set of lingering symptoms.
The World Health Organisation’s classes long Covid as “symptoms that last for at least two months and cannot be explained by an alternative diagnosis”.
Symptoms may be new following an initial recovery from Covid or may have persisted from the initial illness. They may also fluctuate or relapse over time.
– What sort of symptoms are people experiencing?
There's at least a 10% chance, if you catch Covid, of getting long Covid
Common symptoms are fatigue, shortness of breath and cognitive dysfunction – also known as brain fog.
Other symptoms can include a cough, chest tightness or chest pain, palpitations, fever, pain, headache, sleep disturbance, dizziness, pins and needles or numbness, delirium in older people, abdominal pain, nausea, diarrhoea, weight loss, joint or muscle pain, tinnitus, earache, sore throat, loss of taste or smell or even skin rashes.
– Are any particular groups at greater risk?
One in 10 people who become infected are at risk of long Covid, experts have suggested.
Dr Janet Scott, clinical lecturer at the MRC University of Glasgow’s Centre for Virus Research, told the PA news agency that women appear to be at greater risk.
Research suggests people who are vaccinated are less likely to get long Covid.
“There’s at least a 10% chance, if you catch Covid, of getting long Covid,” Dr Scott said.
“Women under 50 are consistently coming up as at higher risk.”
– What are the gaps in our knowledge? What research is happening?
A number of studies are in the pipeline examining who is at greatest risk, how long people can expect to suffer symptoms for and looking at potential treatments.
Professor Amitava Banerjee and his team at the Institute of Health Informatics at University College London are launching a clinical trial to examine whether medicines which are already commonly used can help alleviate symptoms – including an over-the-counter hay fever treatment.
The team is looking to recruit 4,500 people over 10 to 12 months at six hospitals.
The participants will be split into three groups, with a third receiving anti-clotting drugs, a third being given anti-inflammatories, and a third getting a combination of two different antihistamines.
It is hoped the study will help identify underlying mechanisms behind long Covid and whether treatments work.
Prof Banerjee told PA: “Where we would like to get to is to be able to say, ‘Based on these symptoms, we think the underlying mechanism is this… we would like to treat you with that… and we think that people like you get better in six months, or two months or whatever the trajectory is’.
“We’re still quite far from that because there’s so many symptoms that people with long Covid can get. What we call clustering of those has proved difficult and then finding the underlying mechanism has proved difficult.
“In our study, which we’re about to start, we’re trying to do both at the same time. We’re trying to do better at characterising these groups of people who are being referred to long Covid clinics in England and also to try different treatments.
“These treatments, if they work or don’t work, will give evidence to support or to refute these underlying mechanisms.”
– What can I do to avoid getting long Covid?
The simple answer is to avoid getting Covid in the first place.
Prof Banerjee added: “The only way to prevent it is to prevent getting infected.
“The latest analysis, including by ONS (Office for National Statistics), show that although vaccinated people are much less likely to get long Covid than those without vaccination, they still can get infected and they still can get long Covid.
“So this idea that there’s nothing to worry about with high levels of Covid in the population, I think, is misguided. I think we should be doing more to educate people.”
– Is there support available now?
The first port of call is a GP, who can rule out whether or not something else could be causing symptoms, such an anaemia or thyroid problems or another respiratory condition.
People can also be referred to long Covid clinics in England, with some able to be referred to specialists in Scotland.
The website www.yourcovidrecovery.nhs.uk offers help and support for those with ongoing symptoms.
“This has been set up to give advice about specific symptoms, things like sleep, whether to exercise or not to exercise, whether to rest or not to rest, that’s a helpful resource,” said Dr Scott.
She said she has also been recommending a book called Recovery: The Lost Art of Convalescence.
“If you’ve got long Covid, it’s useful to be able to take some steps to optimise life and wellbeing now without having to wait for the research,” she added.
“I think the things to do are about good convalescence – good sleep, good diet, exercise but not too much exercise, rest but not too much rest, which I think is good advice for anybody coming out of any serious illness.”
