No, a Common Cold Will Not Show Up on a COVID-19 Test
COVID-19 tests are highly specific for SARS-CoV-2 and do not cross-react with common cold viruses, including other coronaviruses that cause the common cold. 1, 2
Why COVID-19 Tests Don't Detect Common Colds
Test Specificity and Design
RT-PCR tests target specific SARS-CoV-2 genetic sequences that are unique to this virus, including the RNA-dependent RNA polymerase (RdRp), open reading frame (ORF1), envelope (E), and nucleocapsid (N) genes. 1, 2
These genetic targets have no overlap with common cold viruses, including rhinoviruses, adenoviruses, or seasonal coronaviruses (229E, OC43, NL63, HKU1). 2
The specificity of both PCR and antigen tests approaches 100% (95% CI: 96% to 100% for PCR; 100% for antigen tests), meaning false positives from cross-reactivity are essentially non-existent. 1
What Can Cause False Positives
The primary cause of false positive COVID-19 tests is sample cross-contamination in the laboratory, not cross-reactivity with other respiratory viruses. 1, 3
Antibody tests may show false positives due to cross-reactivity with other coronaviruses, but this does not apply to the standard diagnostic tests (PCR or antigen) used to detect active infection. 1, 4
Substances like rheumatoid factor or heterophile antibodies can interfere with antibody tests, but again, these are not the tests used for diagnosing acute COVID-19. 1
Clinical Implications
If You Have Cold Symptoms and Test Positive
A positive COVID-19 test in someone with cold-like symptoms means they have COVID-19, not a common cold. 2, 3
COVID-19 and the common cold can present with overlapping symptoms (runny nose, sore throat, cough), but the test will only detect SARS-CoV-2. 5
If You Have Cold Symptoms and Test Negative
A negative test likely means you have a common cold or other respiratory virus, though false negatives can occur with COVID-19, particularly if tested too early or too late in the infection course. 1
For symptomatic individuals with high clinical suspicion, a negative antigen test should be confirmed with PCR (NAAT), as antigen tests have lower sensitivity (73% average) compared to PCR (97%). 1, 5
Common Pitfall to Avoid
Do not assume that cold symptoms automatically mean a negative COVID-19 test is accurate. If you have significant symptoms within 5 days of onset and high exposure risk, confirm a negative antigen test with PCR testing, as the sensitivity of rapid tests is imperfect. 1, 5