The Surest Way to Tell You Have COVID-19

Michael Martin
·2 min read

COVID-19 has dozens, maybe even hundreds, of potential symptoms. Many of them overlap with more minor illnesses and can be confused with colds, flu or just feeling run-down. But experts say one symptom is almost definitive of coronavirus: A loss of taste or smell. According to a Jan. 5 study published in the Journal of Internal Medicine, 86% of patients with mild cases of COVID-19 experienced a loss of taste and smell. That parallels an earlier study reported on by Scientific American, in which about 80 percent of COVID patients reported those disturbances. "Smell loss is so common in people with the disease that some researchers have recommended its use as a diagnostic test because it may be a more reliable marker than fever or other symptoms," the publication said. Read on, and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had Coronavirus.

Reasons for taste, smell loss unclear

Experts aren't sure why this happens, just that it's widespread. Last month, Dr. Anthony Fauci, the nation's leading infectious-disease expert, said "the rather frequent occurrence of loss of smell and taste, which precedes the onset of respiratory symptoms" was "of particular interest" to researchers.

One theory is that the virus first takes up residence in nasal cells. So far, research suggests "that the primary attack of the coronavirus is in the nose, in the nasal epithelium, which is the skinlike layer of cells in charge of expressing odors," said Leo Nissola, MD, last month. "It seems like the virus assaults support cells and stem cells in the nose."

He added: "These cells maintain the balance and signal the brain. In some patients, when infected with COVID, that balance is disrupted, and that leads to a shutdown of neuronal signaling, and therefore of smell."

In some people, that loss can linger. A July CDC study found that loss of taste or smell lasts for an average of eight days, but some people experience it for weeks after their initial infection. The Journal of Internal Medicine study found that after two months, 15% of people had not regained their lost senses.

RELATED: COVID Symptoms Usually Appear in This Order, Study Finds

The surest way to tell if you have COVID-19

A loss of taste or smell can signal you have the coronavirus. To be sure, get a test—a PCR test is considered the gold standard—or talk to a medical professional. And do everything you can to prevent getting—and spreading—COVID-19 in the first place: Wear a face mask, get tested if you think you have coronavirus, avoid crowds (and bars, and house parties), practice social distancing, only run essential errands, wash your hands regularly, disinfect frequently touched surfaces, and to get through this pandemic at your healthiest, don't miss these 35 Places You're Most Likely to Catch COVID.