Even though just under one million people in the UK were suffering from long Covid in June, according to official figures, it’s a condition that is not yet fully understood.
And as restrictions are relaxed across the four nations, there are fears that more people will suffer from it as infection rates continue to rise.
Hundreds of thousands of people in the country have been battling long Covid for at least a year, according to Office for National Statistics data, and experts have warned there could soon be 10,000 new cases of it a day.
So, what is long Covid?
Here’s everything you need to know.
What is long Covid?
It’s a condition that can cause debilitating respiratory, cardiological and neurological symptoms.
However, there’s not yet a universally-agreed definition of long Covid.
Scientists are working to find out why some people experience long Covid, while others recover quickly from the virus.
Some think long Covid symptoms are caused by live virus reactivating in the body, while others believe it could be an autoimmune problem with the body attacking itself.
There is also a theory that it might be caused by an underactive immune system, or one that is damaged by the original Covid infection.
Women are more likely to be affected by long Covid than men, and the condition can also affect young and healthy people, as well as children.
Is there a test for long Covid?
At the moment, there are no tests to diagnose long Covid.
But scientists say a simple blood test to detect patients with the condition could be developed within six to 18 months.
Imperial College London researchers have detected irregularities in the blood of people with long Covid which could help to make a test for the condition.
Early research from the pilot study identified autoantibodies common among people with long Covid symptoms, while these were not present in patients who recovered quickly from the virus or those who were never infected.
Autoantibodies are antibodies that mistakenly target the body’s own tissues or organs, leading to inflammation or damage and often causing fatigue and other symptoms.
Professor Danny Altmann of Imperial College London, who was leading the research, told the BBC: “I’m famously optimistic, so I’d hope that within six months we’d have a simple blood test that you could get from your GP and that I think could have quite a big impact for people who don’t feel they’ve managed to convince their GP or accessed specialist care because instead of being my word against yours, it has a diagnostic test.”
What are the symptoms of long Covid?
Latest ONS figures show there are 962,000 people in the UK with multiple Covid symptoms four weeks after initial infection.
While long-term symptoms are broad and can vary, the most commonly reported ones are: fatigue, shortness of breath, chest pain or tightness, problems with memory and concentration, difficulty sleeping, heart palpitations, dizziness, pins and needles, joint pain, depression and anxiety, tinnitus, earaches, feeling sick, diarrhoea, stomach aches, loss of appetite, a high temperature, cough, headaches, sore throat, changes to sense of smell or taste and rashes.
Scientists think the chances of having long-term symptoms does not seem to be linked to how ill people are when they first get Covid.
Those who develop mild symptoms initially can still suffer from long-term problems.
If you think you may be suffering from long Covid, you should contact your GP and make an appointment.
England has set up 89 long Covid clinics to help those suffering with the condition, but BBC Panorama found that four of them were only seeing patients that were originally hospitalised with the virus, and 10 had waiting lists of more than 100 days.
Scotland does not currently have specialised clinics, but the government told the BBC it was investing £2.5million in research.
How long does long Covid last?
Many people recover from Covid in just a few days or weeks. The vast majority will make a full recovery within a period of 12 weeks.
But for those suffering from long Covid, it is currently unclear how long recovery may take.
Around 385,000 people in the UK are estimated to have been suffering with symptoms of the virus for more than a year, ONS data shows.