One in three people will show long Covid symptoms three to six months after being infected, a new study suggests.
Until now long Covid has been self-diagnosed with research based on small scale studies.
But the Oxford study found the most common symptoms were breathing problems, abdominal symptoms, fatigue, pain and anxiety or depression.
When looking solely at Covid-19, the researchers also found that different groups were affected by long-lasting symptoms in different ways.
For example older people and men had more breathing difficulties and cognitive problems, whereas young people and women had more headaches, abdominal symptoms and anxiety or depression.
Patients admitted to hospital were more likely to suffer cognitive problems like brain fog and fatigue compared to people who did not need to be admitted, and people who did not need hospital care were more likely to have headaches than those who needed to be admitted.
The study, which analysed health records of more than 273,000 people who had Covid-19 and 114,000 who had flu in the US, outlined nine long Covid symptoms and the proportion of people who were suffering between 90 and 180 days after initial infection:
– Abnormal breathing – 8 per cent
– Abdominal symptoms – 8 per cent
– Anxiety depression – 15 per cent
– Chest/throat pain – 6 per cent
– Cognitive problems such as ‘brain fog’ – 4 per cent
– Fatigue – 6 per cent
– Headache – 5 per cent
– Muscle pain – 1.5 per cent
– Other pain – 7 per cent
When taking all factors into account, the research team estimated that 37 per cent of people who had a Covid-19 infection had at least one long Covid symptom three to six months after infection.
But the authors stressed there were “important caveats” which meant the results might not be generalised – namely that people included in the study with both flu and Covid could have been “iller” than those in the general population because they had sought medical help for their symptoms.
Dr Taquet said: “Over one third of patients were diagnosed with at least one of the long Covid symptoms between three and six months after their Covid-19 illness.
“The severity of the illness, age and sex affected the incidence and profile of long Covid symptoms.
“Similar symptoms were seen in people after influenza but they occur and co-occur less commonly.”
Health officials have warned that this year’s flu season could be particularly troublesome as immunity to influenza viruses waned during the pandemic.
The Government is hoping that more people than ever will get their flu jab, with over-50s and clinically vulnerable people being called forward to get a vaccine.
Professor Paul Harrison, who headed the study which has been published in the journal PLOS Medicine, from the Department of Psychiatry at the University of Oxford, said: “There are various post-viral conditions recognised and many of us who have experienced flu know how you don’t always feel completely better as quickly as you’ve been hoping or expecting to.”
The Office for National Statistics estimates that 970,000 British people are suffering ongoing symptoms after a Covid-19 infection.
The figures, based on self-reported symptoms, also suggest 384,000 people are still living with symptoms a year after infection.
Separate ONS estimates, based on data from participants of the Coronavirus Infection Survey who had a lab-confirmed case of Covid-19, suggest that between 3% and 12% of people have symptoms 12 weeks after infection.