Almost 36 million people were diagnosed in 2021, and 60% of them reported accompanying losses in smell or taste, according to the study by Mass Eye and Ear, which is affiliated with Harvard Medical School, Boston. The study was published in The Laryngoscope.
Most people fully regained the senses, but about 24% didn’t get smell back completely, and more than 3% had no recovery, the researchers reported. The numbers were similar among those who lost the sense of taste, they added.
“Many people never fully recovered,” Neil Bhattacharyya, MD, professor of otolaryngology and one of the study’s authors, told Fortune, estimating that up to 6 million people still have lingering symptoms. “If you lost your sense of smell, did you get it back? There’s about a one in four chance you didn’t. That’s terrible.”
Researchers looked at the records of 30,000 adults who had COVID-19 in 2021. They reported that patients who suffered more severe cases were less likely to regain some or all their senses.
Some patients said they lost appetite because they couldn’t smell food. There’s concern, too, about losing the ability to smell gas and smoke, spoiled food, and dirty diapers.
People with symptoms should see their doctors, Dr. Bhattacharyya said. The symptoms might be caused by something other than lingering COVID-19 effects and might be treatable.
A version of this article first appeared on WebMD.com.