Some reports say that people who have been ill with COVID-19 may experience symptoms for weeks or even months. However, if people are not ill enough to have been tested or admitted to hospital, these individuals may not be picked up in NHS routine data or research. That makes it difficult to know how common long-lasting symptoms are, and if they are definitely symptoms of COVID-19.
Because COVID-19 is a new illness, we are learning about it all the time. At first, it was assumed to be a flu-like illness, with people who had mild symptoms recovering within a couple of weeks. Although many people do seem to recover quickly, some have reported much longer-lasting symptoms, including extreme fatigue, aching muscles and loss of sense of smell and taste.
At present, there are no reliable studies to say how long it takes people to recover from COVID-19 completely, what persistent symptoms they have or how long some people might experience them for.
Several media sites have carried stories about a doctor who has himself experienced long-lasting symptoms, and from a researcher who says his ongoing study shows “about 10%” of people experience symptoms for at least 25 days.
At present, the basis for the story is anecdotal evidence. Dr Paul Garner, an infectious disease expert and professor at the Liverpool School of Tropical Medicine, wrote in the BMJ about his own experience of having extreme fatigue and “bizarre symptoms”, including tinnitus and pins and needles, for seven weeks after becoming ill with what was likely to be COVID-19 (though he was not tested for the virus). A follow-up blog said that he had experienced several “relapses” of exhaustion in the following three weeks, after thinking he had recovered.
A researcher, Dr Tim Spector, professor of genetic epidemiology at King’s College London, has been working with data from a symptom-tracking app, downloaded by more than 3 million people. He is reported in the Financial Times as saying his data shows about 10% of people still have symptoms after 25 days and 5% after a month. However, these data do not seem to have been published on the study website.
There is no information from the WHO or NHS about how long people are likely to experience symptoms of COVID-19.