evidence: What to know - COVID-19 testing can help you know if you have COVID-19 so you can decide what to do next, like getting treatment to reduce your risk of severe illness and taking steps to lower your chances of spreading the virus to others. Viral tests look for a current infection with SARS-CoV-2, the virus that causes COVID-19, by testing specimens from your nose or mouth. [...] Nucleic acid amplification tests (NAATs), including PCR tests, are more likely to detect the virus than antigen tests. NAATs tests are the "gold standard" for COVID-19 tests.