Losing Your Sense of Smell Is No Longer a Reliable Sign of COVID

The presence or absence of smell and taste loss is no longer a reliable way to tell if you’ve got COVID or not.

After looking at the National COVID Cohort Collaborative database—one of the largest collections of clinical data in the country for COVID research—researchers found that the loss of smell as a key indicator of COVID infection has dropped drastically over time.

Evan Reiter, MD, lead author of the study, professor of otolaryngology in Virginia Commonwealth University’s School of Medicine, and medical director of VCU Health’s Smell and Taste Disorders Center, told Verywell that early in the pandemic, “a viral syndrome with smell loss was very likely to be COVID, but this is not true today.”

Here’s what you need to know.

COVID Symptoms Have Changed Over Time

For the recent study, the researchers focused on data from specific periods when there were peaks in COVID cases. From there, they identified patients who had and did not have smell and taste loss within two weeks of getting a COVID diagnosis.

In 2020, smell and taste loss for the Alpha and Delta COVID variants was more common and even touted as being a classic sign you were infected. With the emergence of newer variants like Omicron and XBB, the researchers wanted to see if the risk of losing those senses is different now.

Instead of looking at the absolute risk of loss of smell and taste, the researchers wanted to see how much the risk changed when they compared the earlier days of the pandemic to more recent times. What they noticed was that from 2022 to early 2023, the risk of smell loss with COVID was only about 6% of what it was back in 2020.

Why Did the Risk of Smell and Taste Loss with COVID Drop? 

The researchers say it’s not clear why the risk of smell and taste loss with COVID has decreased so much, but they’ve got some theories.

Reiter said it could be the protective effect of immunity from vaccines or a previous COVID infection—for example, maybe the body’s sense of smell has more protection against damage from the virus. It’s also possible that differences in the virus’s spike proteins as it has mutated have affected its ability to target smell-receptor (olfactory) neurons.

Jill Foster, MD, director of the Division of Pediatric Infectious Diseases at the University of Minnesota, told Verywell that even though the mechanism isn’t totally understood, our ability to smell is complex, and there are many ways the sense can go wrong.

Foster explained that scent first has to come into contact with a receptor in your nose. Then, the message received from the scent gets transmitted to different parts of the brain for processing. Having a cold can plug those receptors, and that’s why you may temporarily lose your sense of smell and taste when you’re sick.

However, Foster said that “COVID goes one step further and can damage the receptors, the nerves that carry the message, and/or the part of the brain that decodes the message.”

Overall, Foster said it’s hard to predict who will lose their sense of smell and taste from COVID, and whether those symptoms will turn out to be long-lasting.

What Are the Common Symptoms of COVID Today?

Recent reports have included that fever is the most common non-respiratory symptom of COVID. Reiter said that symptoms like congestion and a runny nose also seem to be more common.

According to Reiter, the current symptoms of COVID are similar to those seen in prior waves, but the illness seems to be milder and harder to tell from other non-COVID viral upper respiratory infections.

Foster said that while cough, shortness of breath, fatigue, body aches, and, less commonly, sore throat and diarrhea, are other symptoms to watch out for, “it’s important to remember that someone can have COVID-19 and have no symptoms at all.”

Remember that having a single negative antigen test result cannot rule out COVID. According to the Centers for Disease Control and Prevention (CDC), you should test again (at least once) in 48 hours if you’ve had a negative at-home COVID test but you have symptoms. If you don’t have symptoms and have tested negative twice, the CDC recommends taking a third test 48 hours after the second to be sure. To avoid having to do multiple tests, you might want to ask your provider if it would make more sense to have a PCR test done.

Foster cautioned that even then, testing is not perfect.

“It requires testing at the right time of the disease, getting a good specimen from the nose, and being able to perform the test correctly,” she said. “Make sure you test regularly and administer the test properly to detect if you have COVID-19 and seek appropriate care.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.