What Long COVID really is
Long COVID — also called post-COVID syndrome, post-acute sequelae of SARS-CoV-2 (PASC), or long-haul COVID — is the clinical condition that manifests when symptoms persist for 12 weeks or more after acute SARS-CoV-2 infection and cannot be explained by an alternative diagnosis.
The World Health Organization formally recognizes it with ICD-10 code U09.9. Population studies estimate that between 10 and 30 percent of people who experienced SARS-CoV-2 infection — including mild cases — develop some degree of Long COVID.
Long COVID is not exhaustion, not psychological, not imaginary. It is an immune and inflammatory dysregulation that medicine can measure, intervene, and, in many cases, modulate.