Almost a tenth of people who contract Covid-19 in Abu Dhabi suffer lasting symptoms, a study has suggested. The vast majority of the others make a full recovery. The study of 2,000 former coronavirus sufferers in Abu Dhabi found 92 per cent recovered with no lasting symptoms, while 8 per cent experienced lasting effects - similar to international findings, officials said. Five per cent experienced symptoms for more than eight weeks. Long Covid, a mysterious condition that affects a small but significant percentage of people who recover initially from the coronavirus, causes symptoms including fatigue, shortness of breath and depression. “Mood and energy levels were the most common symptoms of long Covid, with 52 per cent feeling tired, 35 per cent having a persistent cough and 27 per cent reporting a negative mood,” said Department of Health Abu Dhabi, which conducted the study. It said that 52 per cent of respondents with long Covid "were able to do their day-to-day activities as normal”. The study also found adults were twice as likely as children to be taken to hospital. The risk for people aged 40 or older was 2.5 times as great as the risk for children. However, the need for hospital treatment was “rare for those aged 19 or under without comorbidities,” said the department. The risk was higher in certain groups, including smokers, vapers, and people who were severely overweight or had asthma. “Comorbidities were present in many people who developed severe Covid-19 symptoms, or required hospitalisation,” said the department. In total, 6 per cent of smokers and 13 per cent of vapers who took part in the study required treatment in hospital. The results also suggested obese people were three times more likely to need hospital care than those of a healthy weight. Of those who required treatment in hospital, 31 per cent were obese, 24 per cent had asthma, 14 per cent had a respiratory condition, 14 per cent had high blood pressure and 6 per cent had diabetes. People who suffer severe Covid-19 are more at risk of lingering symptoms. But long Covid can also affect those who had mild initial illness. More than 200 symptoms of the condition have been identified, including hallucinations, tremors, itchy skin, changes to the menstrual cycle, sexual dysfunction, heart palpitations, bladder control issues, shingles, memory loss, blurred vision, diarrhoea and tinnitus. Fatigue and brain fog are the most common. The cause of long Covid is still not understood. But one theory is that its symptoms could be caused by an autoimmune response to the initial infection. Autoimmune disease happens when antibodies, which the body makes to fight illness, mistakenly attack normal cells. Researchers from Imperial College London found a pattern of rogue antibodies in the blood of a small number of people with long-Covid symptoms. The so-called autoantibodies were not present in people who recovered quickly. The researchers hope to develop a blood test to diagnose the condition, which will be ready in six to 18 months.