Of this group, 23% were severely impaired or had entirely lost their sense of smell. Those with a diminished sense of smell may also struggle to detect dangers such as spoiled food, gas leaks, and smoke, experts say. To measure olfactory function, the team used a clinical tool: the University of Pennsylvania Smell Identification Test (UPSIT). "These results suggest that health care providers should consider testing for loss of smell as a routine part of post-COVID care," said Horwitz. Horwitz cautions that the study team did not directly assess loss of taste, which often accompanies problems with smell.