What we know and don’t know about long Covid

Whether you call it long Covid or post-acute Covid-19 or just identify yourself as a long-hauler, the constellation of prolonged symptoms after Covid-19 infection has become all too familiar. About one-third of people who were sick enough to need hospitalization — including supplemental oxygen or mechanical ventilation to breathe — still struggle with problems affecting their bodies and their minds four weeks or more after the first onset of symptoms. About 1 in 10 people who had Covid but were never admitted to a hospital report they experience bewildering brain fog, shortness of breath, muscle weakness, or crushing fatigue in the months after the first signs of their initial illness. Some see no end in sight; others seem to recover. To help understand how to recognize and treat this mysterious condition, researchers from Harvard and Columbia culled the scientific literature to guide treatment for nine organ systems where the SARS-CoV-2 virus does its damage.