Feeling sick but testing negative? Doctors explain why

(NEXSTAR) – You’ve got the sore throat, runny nose and cough (or any of the other most common COVID-19 symptoms right now), but when you swab your nose and take a test, it comes out negative. Is there a chance you still have COVID-19? Could it be something else?

The answer – to both questions – is yes.

“If you are feeling symptomatic and you test negative for COVID-19, usually the most likely reason is you’re infected with something else besides COVID-19,” said Dr. Andrew Pekosz, a virologist and professor at Johns Hopkins Bloomberg School of Public Health, during a media briefing last week.

After all, two other respiratory viruses, influenza and RSV, are circulating at especially high levels this winter, and all three illnesses have overlapping symptoms.

But Pekosz went on to say that a negative test doesn’t really change much as far as next steps go.

“If you’re feeling sick, there really should be no difference whether you’re testing positive for COVID-19, flu or RSV,” he said. “If you’re feeling sick, stay home, take care of yourself. If you’re in a high-risk group, seek medical attention so you can get some advice as to what to do. There are a lot of viruses out there that are causing similar spectrums of diseases. So if you’re feeling sick, you are sick.”

Dr. Keri Althoff, an associate epidemiology professor at the Bloomberg School, suggested waiting 24 to 48 hours and then testing again. You may get a positive test result if you have COVID-19 and your viral load builds up.

Guidance from the Centers for Disease Control and Prevention notes that a negative COVID-19 test result does not necessarily mean you’re free of infection. Even if the virus is not detected, it could still be there in small amounts.

If you have symptoms of the virus and still are testing negative, the CDC says, “You may have COVID-19, but tested before the virus was detectable, or you may have another illness, such as the flu.”

You may also consider getting a PCR test at a testing site, which is more sensitive and may detect the virus earlier on.

At-home and lab tests are still good at catching COVID-19 infections, despite mutations and changes in variants, Pekosz said.

Getting tested at a doctor’s office can also help you identify what’s making you sick, and get you access to the appropriate treatment.

“For both flu and for COVID, we have antivirals that work if taken early after signs of symptoms,” Pekosz told Nexstar. “So particularly if you’re in a high-risk group, it’s good to know that. … Those are important tools that we really have to keep using.”