If you don't feel well, you may worry that you have COVID-19. The only way to know for sure is to take a test. At-home tests can tell whether you have the virus right now. More specialized antibody ...

Ducharme is a contributor to TIME. A nurse practitioner administers COVID-19 tests in the parking lot at Brockton High School in Brockton, Mass., on Aug. 13, 2020. A nurse practitioner administers ...

Vitamin D tests involve taking a blood sample to measure the vitamin D levels in your bloodstream. There are two forms of vitamin D in the blood: 25-hydroxy vitamin D, or calcidiol, and 1,25-dihydroxy ...

At-home STD tests offer convenience and privacy while testing for sexually transmitted diseases (STDs). These diseases are also called sexually transmitted infections (STIs). If you're sexually active ...