After multiple hypotheses and lots of speculation, one of the many mysteries surrounding COVID-19 might be finally solved.
It turns out that a haywire immune response in our olfactory system is the reason there are some people who still haven’t got their sense of smell back, even after their symptoms are gone. Patients with long-term smell loss had fewer olfactory sensory neurons. Olfactory sensory neurons are cells in your nose which detect smells and send that information up to the brain. People who had lingering loss of smell had, on average, 75% less of these neurons in comparison with healthy people.
While most COVID-19 patients regain their sense of smell within a couple of weeks of their infection, as many as 7% of patients won’t get their smell back for a year or more. While the sense of smell might not seem like the biggest deal, smell plays a huge role in the creation of memories and our emotions.