Nasopharyngeal Covid-19 swab NurPhoto via Getty Images Many who’ve had a nasal Covid-19 test performed on themselves have described it as feeling like that swab got as far back as their brains ...

Comparison between nasopharyngeal swab and nasal wash, using culture and PCR, in the detection of potential respiratory pathogens. BMC Res Notes 2011;4:122-122.

A COVID-19 home test in the U.S. comes with a swab to swirl in the nostrils. But some users say they're swabbing the throat too — even though that's not what the instructions say to do. "They ...