More than two million British adults may be suffering from the long-term after-effects of contracting Covid-19, according to a new survey.
A new study of 500,000 Brits shows about a third of people who report they have coronavirus symptoms have had one or more symptoms that persist for at least 12 weeks.
The phenomena, known as 'long Covid', is not yet fully understood, but includes a range of symptoms that persist after a person has broadly recovered from their initial Covid-19 infection, including fatigue, coughs, chest pain, headaches and muscle pain.
The study, which took place between September 2020 and February 2021, found that 37 per cent of those who said they had contracted the disease continued to suffer from at least one symptom lasting 12 weeks or more, with 15 per cent saying they had three or more symptoms for at least 12 weeks.
Researchers also found long-term issues were more common in women, and become more likely as people age. Increased weight, smoking, lower incomes, having a chronic illness, and being hospitalised were also linked with long Covid.
Professor Paul Elliott, director of the REACT programme at Imperial College London, which conducted the study, said their findings should concern officials as it may mean the disease has long-term effects on healthcare systems.
"Long Covid is still poorly understood but we hope through our research that we can contribute to better identification and management of this condition, which our data and others' suggest may ultimately affect millions of people in the U.K. alone," he told the BBC.
Another study conducted by researchers at University College London and King's College London found one in six middle-aged people reported long Covid symptoms, but this fell to one in 13 among younger adults.
The U.K. government has pledged $70 million (£50 million) for research into long Covid, and its National Health Service (NHS) has opened more than 80 long Covid assessment services across England.