The World Health Organization has issued new clinical advice for treating Covid-19 patients, including those displaying persistent symptoms after recovery.
A study by the Office for National Statistics in the UK estimated that one in five people has symptoms that persist after five weeks, and one in ten has symptoms for 12 weeks or longer after acute coronavirus infection.
An article published in The Lancet medical journal last month by healthcare workers affected by long Covid listed ongoing symptoms including renal impairment, new-onset diabetes and lung disease.
WHO also said that it was advising the use of a pulse symmetry to measure oxygen levels of Covid patients at home to see if they are deteriorating and need hospitalisation.