New data from the Office for National Statistics based on a survey of patients found the numbers of patients with persistent symptoms after 12 months jumped from 70,000 in March to 376,000 in May.
Overall, the ONS said an estimated one million people had self-reported signs of long Covid which last for more than four weeks.
The effects of long Covid were reported to be affected the day-to-day activities of 650,000 people, with 192,000 of those saying their ability to undertake day-to-day activities had been limited a lot.
Fatigue was the most common symptom reported, with 547,000 people affected. A total of 405,000 people reported a shortness of breath, while 313,000 had muscle aches.
More than a quarter of a million patients, 285,000 people, said they had difficulty concentrating.
According to the ONS the prevalence of long Covid was higher among those aged between 35 and 69.
Women were more likely to be affected than men, along with those living in the most deprived areas and staff working in health and social care.
Many of these groups are know to have a higher risk of infection during the pandemic.
The prevalence of long Covid was lowest among people from an Asian background.
A review of more than 300 studies by experts at the National Institute for Health Research (NIHR) in March warned many patients were struggling to access testing and help from the NHS to treat their symptoms.
The NIHR suggested long Covid could be made up of four distinct syndromes which can mean for some patients active disease and organ damage leading to debilitating symptoms and disability. Some patients experienced effects on their brains while others suffered blood clots and inflammation.
It also warned there was evidence some long Covid patients were actually getting worse.
Dr Elaine Maxwell, scientific advisor at the NIHR, told The Independent: “These figures are as anticipated and reflect the fluctuation in historic rates of infection. They confirm suspicions that there are different natural histories within the umbrella term ‘long Covid’.
“There is a cohort of people who have symptoms that resolve without treatment within 12 weeks and an increasing number whose symptoms have lasted 12 months or more, but as yet we don’t know how much longer they will last. Recent research from the USA shows 14 per cent of people develop a new medical diagnosis after a Covid-19 infection, and this is higher than after other viral pneumonias.”
She added: “People with long Covid lasting over 12 months were infected in the first wave. We know significantly more people have been infected between May 2020 and today and we should expect to see the number of people with long-term long Covid rise over the course of 2021. Given it is most commonly reported in working-age people, this is likely to have a significant impact not only on health services but on society as a whole.
“The NHS needs to look beyond rehabilitation and urgently develop a strategy to manage this growing problem.”
The NHS has invested millions in a network of long Covid clinics but anecdotal reports from patients suggest some are struggling to access treatment after an initial assessment while others face long waits to be seen.
The All-Party Parliamentary Group on Coronavirus has warned some patients face waiting over 100 days for treatment.
Chair Layla Moran MP said: “These figures should serve as a wake-up call to ministers that they must urgently fix the postcode lottery of care facing those with long Covid.
“Hundreds of thousands of people around the country are struggling with the debilitating impact of this condition yet are still not receiving the care they need.
“Our research has found that long Covid patients are waiting over 100 days for treatment, while in some areas the clinics promised by the government have been delayed.
“The government must take steps to alleviate the suffering faced by those with this cruel disease, and factor in the risks posed by long Covid as restrictions are eased.”
Julie Stanborough, head of health analysis at the ONS, said: “Around one million people in the UK were experiencing self-reported long Covid at the beginning of May, with nearly two-thirds experiencing a negative impact on day-to-day activities. Self-reported long Covid was most common in people aged 35 to 69 years, women, those living in the most deprived areas, and those living with an existing disability or health condition.
“Our analysis also shows that health and social care workers had a higher prevalence of self-reported long Covid than those working in other sectors, but this was largely driven by the risk of initial infection and other socio-demographic factors such as age, sex and location.”
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