About 14 years ago, Chrissi Kelly lost her sense of smell after a virus. Doctors told her to just live with it. She didn't take that advice lying down - she founded two nonprofit patient groups and co-published over 30 academic papers. Turns out, she had a point.

Researchers estimate that up to 22 percent of the population lives with smell impairments like hyposmia or anosmia. Yet for decades, the medical establishment basically shrugged. Then COVID-19 came along and infected 780 million people (per WHO), many of whom suddenly couldn't smell their morning coffee. That got their attention.

Smell loss is now linked to an astonishing 139 neurological, physical, and congenital conditions - from alcoholism to Zika. It can be an early warning sign for Parkinson's, Alzheimer's, and Lewy body dementia. It's also tied to depression, schizophrenia, and autism. The olfactory bulbs, those “two little earthworms lying in their crypts” as Kelly poetically puts it, are apparently the brain's most vulnerable entry point for viruses, toxins, and possibly microplastics.

The good news? Olfactory training - basically physical therapy for your nose - can help. About 30 percent of patients improve after months of sniffing lemon, rose, clove, and eucalyptus twice daily. A 2024 meta-analysis found positive effects across 36 studies. Pair it with a steroid sinus rinse, and up to 50 percent see changes. It's not a miracle cure, but it's cheap, simple, and beats the old advice of "learn to live with it."