How COVID-19 Causes the Loss of Taste and Smell

Interacting with food is an incredibly sensual experience. Imagine the smell of an oven roast or even the smell of freshly picked lemons. You would be excited to taste the imaginations. But what happens when you lose your sense of smell to go along with it? Our senses of smell and taste are interdependent, so if you lose one of these senses, you lose the other one too.

What is Anosmia?

Anosmia is a disorder where one loses their ability to smell. There are various forms: Congenital anosmia is when someone is unable to smell at birth, and hyposmia describes the diminishing sense of smell that develops over time.

In understanding anosmia, it is critical to first grasp the science of smell. Whenever we breathe air, particles pass through our nose and bind to the olfactory receptors beneath the cribriform plate. The nerve cells come into direct contact with the air we breathe, connecting the nose with the brain through the cribriform plate. Patients with anosmia damage the plate, which damages the neurons which in return causes the lost of senses.

COVID-19 Relation

A majority of COVID-19 patients experience some level of anosmia, most often temporary. COVID-19 patients are 27 times more likely to have smell loss but are only around 2.2 to 2.6 times more likely to have fever, cough or respiratory difficulty, compared to patients without COVID-19, according to Harvard Medical School.

Some studies have hinted that anosmia in COVID-19 differs from anosmia caused by other viral infections. For example, COVID-19 patients typically recover their sense of smell over the course of weeks—much faster than the months it can take to recover from anosmia. In addition, many viruses cause temporary loss of smell by triggering upper respiratory issues such as stuffy nose. Some COVID-19 patients, however, experience anosmia without any nasal obstruction.