Some patients who have been infected with SARS-COV-2 have new, recurring, or ongoing symptoms and clinical findings more than four weeks after infection, sometimes after initial symptom recovery. Post-COVID conditions can occur in patients who had varying degrees of illness during acute infection, including those who had mild or asymptomatic infections. Medical and research communities are still learning about these post-acute symptoms and clinical findings.

Post-COVID conditions are being referred to by a wide range of names, including post-acute COVID-19, long-term effects of COVID, long COVID, post-acute COVID syndrome, chronic COVID, long-haul COVID, late sequelae, and others, as well as the research term post-acute sequalae of SARS-COV-2 infection (PASC).external icon Although standardized case definitions are still being developed, in the broadest sense, it can be considered a lack of return to a usual state of health following acute COVID-19 illness. It might also include development of new or recurrent symptoms that occur after the symptoms of acute illness have resolved.

Scientific knowledge is still limited about these effects, including what causes them and how often they occur. Interim terminology will be updated as more information becomes available.