Anosmia is the total or partial loss of your sense of smell. While almost everyone will experience temporary anosmia when they have a common cold, a more severe loss of smell can occur and become permanent. In some rare cases, people are born without the ability to smell.
How does your sense of smell work? When you breathe, molecules in the air come into direct contact with fragile olfactory receptor neurons in your nose. Then, these neurons pass signals through the cribriform plate, a honeycomb-shaped bone in the upper part of the nose. The information then passes through the olfactory bulb and into the brain for processing. When you sustain a head injury, you can damage the receptor neurons at the cribriform plate or injure the olfactory bulb. This is why head injuries are thought to be one of the most common causes of total loss of smell. Nasal obstructions or polyps can also cause anosmia, and these are often treatable.
Aging can also play a large role in a decreased sense of smell. As we get older, the number of neurons in our noses dwindle and we can’t replace them as readily. This is why a very large proportion of the population has some degree of smell loss as they age. Although not all cases of anosmia are treatable, knowing the cause of anosmia can provide insight into what treatment options or resources are available.
If you have questions about anosmia, talk to your doctor today.