Sep 25, 2025 08:39 PM
(This post was last modified: Sep 25, 2025 08:39 PM by C C.)
INTRO: People who suspect that their sense of smell has been dulled after a bout of COVID-19 are likely correct, a new study using an objective, 40-odor test shows. Even those who do not notice any olfactory issues may be impaired.
Led by the National Institutes of Health’s RECOVER initiative and supported by its Clinical Science Core at NYU Langone Health, a team of researchers from across the country explored a link between the coronavirus that causes COVID-19 and hyposmia — the reduced ability to smell.
The results revealed that 80% of participants who reported a change in their smelling ability after having COVID-19 earned low scores on a clinical scent-detection test taken about two years later. Of this group, 23% were severely impaired or had entirely lost their sense of smell.
Notably, 66% of infected participants who did not notice any smelling issues scored abnormally low on the evaluation as well, the authors say. “Our findings confirm that those with a history of COVID-19 may be especially at risk for a weakened sense of smell, an issue that is already underrecognized among the general population,” said study co-lead author Leora Horwitz, MD.
Horwitz, a professor in the Departments of Population Health and Medicine at NYU Grossman School of Medicine, adds that 60% of uninfected participants who did not report olfactory problems also tested poorly during the clinical evaluation.
Hyposmia has long been connected to weight loss, reduced quality of life, and depression, among other concerns. Those with a diminished sense of smell may also struggle to detect dangers such as spoiled food, gas leaks, and smoke, experts say. In addition, scientists have flagged smelling dysfunction as an early sign of certain neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease, which can affect the brain’s scent-processing region.
While past research has identified hyposmia as a symptom of coronavirus infection, most of these studies have relied on patients’ own assessments of their smelling ability. Such subjective measures are not always reliable and cannot effectively track the problem’s severity and persistence, notes Horwitz.
The new study in 3,535 men and women, publishing online Sept. 25 in the journal JAMA Network Open, is the largest to date to examine loss of smell after COVID-19 by using a formal test, the authors say... (MORE - details, no ads)
Led by the National Institutes of Health’s RECOVER initiative and supported by its Clinical Science Core at NYU Langone Health, a team of researchers from across the country explored a link between the coronavirus that causes COVID-19 and hyposmia — the reduced ability to smell.
The results revealed that 80% of participants who reported a change in their smelling ability after having COVID-19 earned low scores on a clinical scent-detection test taken about two years later. Of this group, 23% were severely impaired or had entirely lost their sense of smell.
Notably, 66% of infected participants who did not notice any smelling issues scored abnormally low on the evaluation as well, the authors say. “Our findings confirm that those with a history of COVID-19 may be especially at risk for a weakened sense of smell, an issue that is already underrecognized among the general population,” said study co-lead author Leora Horwitz, MD.
Horwitz, a professor in the Departments of Population Health and Medicine at NYU Grossman School of Medicine, adds that 60% of uninfected participants who did not report olfactory problems also tested poorly during the clinical evaluation.
Hyposmia has long been connected to weight loss, reduced quality of life, and depression, among other concerns. Those with a diminished sense of smell may also struggle to detect dangers such as spoiled food, gas leaks, and smoke, experts say. In addition, scientists have flagged smelling dysfunction as an early sign of certain neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease, which can affect the brain’s scent-processing region.
While past research has identified hyposmia as a symptom of coronavirus infection, most of these studies have relied on patients’ own assessments of their smelling ability. Such subjective measures are not always reliable and cannot effectively track the problem’s severity and persistence, notes Horwitz.
The new study in 3,535 men and women, publishing online Sept. 25 in the journal JAMA Network Open, is the largest to date to examine loss of smell after COVID-19 by using a formal test, the authors say... (MORE - details, no ads)