A loss of smell, and therefore taste, is emerging as one of the most unusual early signs of mild to moderate 2019 coronavirus disease (COVID-19) infection. Although fever, cough, and shortness of breath are the key signs of COVID-19, a recent analysis of milder cases in South Korea found the major presenting symptom in 30 percent of patients was anosmia, or loss of smell. In Germany, more than two in three confirmed cases had this symptom.

One way to test your smell is to use foods, says ear, nose, and throat specialist Erich P. Voigt, MD, director of the Division of General Otolaryngology and Sleep Surgery at NYU Langone Health.

“The pure smell sense would be if you can smell a particular substance that’s not stimulating other nerves,” Dr. Voigt says. “So some examples of that would be if you can smell ground coffee or coffee brewing, or if you can smell someone peeling an orange. That’s the smell sense.”

Of course, failing the smell test on its own does not mean one has COVID-19. Any respiratory virus, such as cold or flu, can affect smell and taste.

“The amount of swelling that can occur in the nose from the viral effect can prevent the smell particles from getting all the way up to the top of the nose where the olfactory nerve is,” Dr. Voigt says. “When that swelling goes down, the sense of smell can return.”

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