A teenager says she has been unable to return to school nearly four months after developing so-called "long Covid".
Keen swimmer Liliana Jackson, 16, tested positive for coronavirus in September and has suffered with nausea, headaches, rashes and fatigue since.
"I thought I would just have a cold and be over it, but I just did not get any better," she said.
Experimental data has suggested one in 10 patients develop long Covid.
Liliana, from Osbournby, near Sleaford, tested positive for the virus eight days after she first developed symptoms.
Despite starting to feel better by October, she said she became "dramatically worse" and was admitted to hospital overnight after developing a full body rash.
She was discharged the next day but said her symptoms continued and on Christmas Day she went to A&E.
"I got really sick to the point that it hurt to touch my skin," she said.
"[It hurt] so bad that when I tried to sleep I couldn't lay down."
She was discharged later the same day and, after consulting her GP again earlier this month, has been referred to a long Covid clinic.
Her mother, Gail, said: "Some days she's ok, other days she can't get out of bed.
"It's hugely upsetting."
What is long Covid?
Long Covid presents as a range of different symptoms suffered by people weeks or months after being infected, some of whom had not been very ill with the initial virus.
Fatigue is the most common problem, but breathlessness, a cough that will not go away, hearing and eyesight problems, headaches and loss of smell and taste have all been reported.
The Office for National Statistics suggests one in 10 people who tested positive for Covid-19 in a household survey still had symptoms 12 weeks later - but this is still experimental.
Danny Altman, a professor of immunology at Imperial College London said it was possible there were as many as 300,000 people with long Covid in the UK.
But he said the research was in its "early stages" particularly among children and adolescent patients.