An Israeli health study of two million people found that most long Covid-19 patients had shrugged off symptoms a year after infection.
But some of those with severe cases say they have never recovered.
Researchers analysed the health records of people provided by Maccabi Healthcare Services, one of the four health funds operating in Israel, and found that more than 70 symptoms linked to long Covid cleared up within 12 months of a mild infection.
The patient samples were limited to Israel and taken before October 2021.
The study, published in the British Medical Journal, found many who recovered from the virus suffered from respiratory problems, palpitations, dizziness, sore throats and problems with concentration, memory and “brain fog”.
“Although the long Covid phenomenon has been feared and discussed since the beginning of the pandemic, we observed that most health outcomes arising after a mild disease course remained for several months and returned to normal within the first year,” the study's authors said.
While the research offered hope to those with a mild form of the virus who had long-term problems, others admitted to hospital with more severe Covid-19 said complications persisted.
One of those is Sohail Anjum, a former Dubai resident now in the UK who picked up Covid-19 in March 2020. He is still struggling with cardiovascular problems almost three years on.
“I was in a coma and wasn’t discharged from the hospital until May 2020,” he said.
“I still suffer fatigue, breathlessness and heart palpitations.
“I recently learnt that the left side of my diaphragm is elevated much higher than it should be and is static.
“That was caused during Covid, which could be affecting the symptoms I currently experience.”
Long Covid symptoms — in pictures
According to World Health Organisation figures, more than 17 million people were hit by symptoms of long Covid in Europe in 2020 and 2021.
Results included in the research covered only early variants of Covid-19 and focused on those swabbed only in Israel.
Children were found to have fewer complications than adults, with most recovering earlier and well within a year.
Those vaccinated were also less likely to have breathing difficulties, the report said.
Doctors said the results could help them to differentiate between long Covid-19 or other ailments by determining when someone had the virus and the severity of infection.
Mr Anjum, 50, said his heart rate regularly climbed to about 145 beats per minute, just from climbing a flight of stairs.
He has since turned to alternative therapies to treat his symptoms and hopes to return to Dubai once his treatment ends.
While Mr Anjum supports more research into the long-term effect on those admitted to hospital with the virus, he is part of an online support group of Covid-19 long haulers in the UK, which has more than 7,700 members.
“The researchers sampled people with mild symptoms who were not even hospitalised,” Mr Anjum said.
“That is like sampling someone with a common cold and saying they will recover in a week.”
Caroline Rousseau, who is French and lives in Dubai, was unable to take the vaccine as she has an allergic reaction to some medications.
The 37-year-old consultant picked up Covid-19 in March 2021, was hospitalised for three weeks and experienced long covid symptoms for more than a year.
“I had several tests and they were negative, but I had the symptoms and then when I tested positive two weeks later I was admitted to Thumbay Hospital with pneumonia," she said.
“When I was released from hospital I was testing negative, but I was still having symptoms of weakness and tiredness.
“My heart rate was very high, then very low and I had not experienced this before so I was worried.
“Also, my brain and memories were like mashed potatoes, I couldn’t remember anything. It was very strange for me, and I also has difficulties with my grip and trying to hold things."
Symptoms persisted until at least August 2021, she said, with her heart rate going as high as 200 beats per minute.
“I started to recover slowly until January 2020, when the symptoms started to reduce. It lasted almost a year until around May 2022.
“I am still not at 100 per cent, people contact me and I can’t remember who they are, but otherwise I have recovered.”