Using a long swab that is mildly uncomfortable when placed through your nasal passages, the clinician (e.g. nurse, doctor, or physician assistant) performing the test (wearing protective equipment or PPE) will twist the swab for 10 to 15 seconds (roughly 5 times) in order to get an adequate sample for the lab to look for the COVID-19 virus under the microscope. (NOTE: there are additional terms used for COVID-19.)
This process is done in both nostrils. Occasionally, the clinician will place the swab down your throat instead for an oropharyngeal sample. Closing your eyes helps lessen the discomfort. It will be over quickly, but getting an adequate sample is important.