Imagine waking up to the aroma of freshly brewed coffee wafting into your bedroom, inviting you to start your day. It seems simple—you know what coffee smells like. But the process of taking that scent in through your nose and processing it with your brain into something you recognize is complex. If something goes wrong and you can’t smell, you can face a host of problems.
Here’s what happens when you smell something
Let’s take your morning coffee, for example. It may seem like you’re smelling one thing, but the scent of coffee is made up of a lot of different odorants that you inhale when you breathe in through your nose. “Most odors are a combination of many odorants, which the brain processes as a smell,” said Eugene Chang, MD, an otolaryngologist at Banner—University Medical Center Tucson.
These odorants are like little keys that unlock the smell nerves, or olfactory neurons, in the upper part of your nose. Each smell nerve is tuned in to unlock and activate a neuron when it detects a certain odorant.
These neurons send an electrical signal and activate a cluster of fibers in the brain that’s called the olfactory bulb. There, the brain processes the complex scent and identifies it— “coffee.”
What can go wrong with your sense of smell
If you notice a change in your sense of smell, talk to your doctor. “In some cases, we can identify the cause of loss of smell. This is important, as there are certain therapies that may help,” Dr. Chang said. Loss of smell might be caused by:
- Viruses. At some point, you’ve probably had a cold and noticed that you can’t smell as well as you usually do. And of course, the loss of smell (and taste) is a telltale symptom of COVID-19 infection. A short course of oral steroids may help in these cases, Dr. Chang said.
- Nasal polyps. People with nasal polyps that interfere with their sense of smell may see improvement with medication or surgical treatment.
- Tumors. In rare cases, tumors trigger a loss of smell, and surgery may help.
- Other causes. With aging, neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease, trauma, or unknown reasons, it’s harder to restore the sense of smell.
The dangers that can crop up when you can’t smell
“When patients come to us with problems with smell, one of the first things we do is remind them of safety concerns,” Dr. Chang said. “Things that we take for granted, such as the smell of a gas leak or the smell of rotten food, can pose significant danger to those without smell.”
But it’s not just safety issues that are problems for people who can’t smell. Scents are associated with pleasure and memories. Losing that connection can lead to depression.
Without aromas, the flavor of food can be flat and dull. People who love cooking struggle to evaluate the flavors in the foods they are preparing. People can lose interest in eating and develop nutritional deficits.
Scientists are studying the sense of smell
If you notice changes in your sense of smell, talk to a healthcare professional. The inability to smell can lead to physical and mental health problems. But often, doctors can diagnose the cause and treat the condition that’s affecting your sense of smell. Dr. Chang’s laboratory, along with others worldwide, is actively researching ways to help improve our sense of smell.
Talk to an expert if you’re concerned about your ability to smell. Banner Health can connect you with a doctor in your area—visit bannerhealth.com.
To learn more about conditions that could affect your sense of smell, read: