Medically reviewed by Kate Colby, MPH People with asymptomatic or mild COVID illness generally test negative after nine days, but a polymerase chain reaction (PCR) test can still be positive for up to ...

Last week, I was about to go on a date, and because I'm severely immunocompromised, we agreed he would take a COVID test using one of my rapid home PCR tests. It was a courtesy—he felt perfectly fine— ...

At-home COVID-19 tests have become commonplace for many households, but knowing when exactly to take a rapid test — or when to throw old ones out — isn't always straightforward. Here's what health ...

When COVID first hit, waiting days for laboratory results from an ultrasensitive polymerase chain reaction (PCR) test was commonplace. Faster tests usable by anyone, anywhere, later became widely ...