Think about the last time you noticed a scent. Maybe it was the aroma of freshly brewed coffee, the sharp, sour smell of a lemon or even that unmistakable scent of your baby after a bath.
Smelling something might seem like a simple process. But taking a scent in through your nose and processing it with your brain into something you recognize is complex. And if something goes wrong and you can’t smell, you can face a lot of problems.
Here’s what happens when you smell something
Let’s take your morning coffee. 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 scents are a combination of many odorants, which the brain processes as a smell,” said Eugene Chang, MD, an ear, nose and throat specialist with Banner – University Medicine.
These odorants work like little keys that unlock some of the five to six million smell nerves (olfactory receptors) in the upper part of your nose. These special cells have hair-like structures called cilia that are sensitive to different odors. Each nerve is tuned in to unlock and activate a neuron when it detects a certain odorant.
These neurons trigger a chemical reaction, send an electrical signal and activate a cluster of fibers in the brain called the olfactory bulb. There, the brain processes the complex scent and identifies it as coffee. The large number of receptors means you can detect a lot of different odors.
What can go wrong with your sense of smell?
Losing your sense of smell is known as anosmia. It doesn’t just impact your ability to detect odors. It can change your relationship with the world around you and affect your daily routines, the pleasure you derive from eating and your overall sense of connectedness.
Talk to your doctor if you notice a change in your sense of smell that doesn’t get better. Pay attention to any changes in your sense of taste as well. “Smell accounts for about 70% of taste. So if you find yourself putting more hot sauce or salt on food, it may be due to a decrease in smell,” Dr. Chang said.
“In some cases, we can identify the cause of loss of smell. This is important, as certain therapies may help,” he said.
Loss of smell might be caused by:
- Viruses: At some point, you’ve probably had a cold, flu or COVID-19 and noticed that you can’t smell as well as you usually do. Your sense of smell usually returns to normal once you feel better. If it doesn’t, a short course of oral steroids may help, Dr. Chang said.
- Nasal congestion: When your nasal passages are blocked, you may lose your sense of smell until they clear up.
- Sinus infections: These bacterial or viral infections can affect the olfactory receptors.
- 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 in the nose, skull or brain trigger a loss of smell. Surgery may help.
- Injury: Accidents or surgery that affect the nose, skull, head or face may damage the olfactory nerve.
- Other causes: With aging or neurodegenerative disorders such as Parkinson’s, Alzheimer’s disease or multiple sclerosis, it’s harder to restore the sense of smell.
Often, the loss of smell can be treated or will come back when the underlying problem clears up. But sometimes, your sense of smell doesn’t return. That can happen from trauma or nerve damage. In those cases, you’ll need to learn ways to manage the impact on your life.
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 a 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, memories and emotional connection. Losing that connection can lead to depression.
Without aromas, the flavor of food and drinks can taste bland, flat or 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.
When to get medical care
“Most of the time, a decrease or loss of smell will get better,” Dr. Chang said. “If your sense of smell isn’t better in two to three months, seeking care is appropriate.”
Contact a health care provider to see if it’s a common issue (like a viral infection) or something more serious. If it’s treatable, you can get care right away. If not, you can begin to learn ways to adapt.
If your loss of smell is permanent, your provider can help you connect with resources, support and online communities for people with anosmia.
How to cope
Your sense of smell gives you important information, so without it you need to find workarounds. For example, if you can’t smell foods, look at visual cues, expiration dates, label information, texture and temperature to make sure your food is safe to eat.
You’ll also want to tell the people around you that you can’t smell, so they can warn you about problems like gas leaks.
You may have emotional reactions to losing your sense of smell, such as frustration, sadness and loss. Talk to your provider about your physical and emotional concerns and challenges so they can help you find ways to manage them.
Treating loss of smell
Depending on what’s causing your loss of sense of smell, these treatments may help:
- Saline sinus irrigations to clear nasal passages.Sinus infection
- Antihistamines or steroids to reduce inflammation from allergies or sinusitis.
- Antibiotics to treat bacterial infections.
- Surgery to remove polyps or treat sinuses.
- Training to expose the olfactory nerve to a variety of scents.
Your health care provider can explain how treatment works and how likely you are to regain your sense of smell over time.
Scientists are studying the sense of smell
Dr. Chang’s laboratory, along with others worldwide, is actively researching ways to help improve our sense of smell. Studies are focusing on regenerative therapies, nerve regeneration and advancements in neurology that may create new treatment options.
The bottom line
Talk to a health care provider if you notice changes in your sense of smell that aren’t going away. The inability to smell can lead to physical and mental health problems. But often, doctors can diagnose the cause and treat the condition affecting your sense of smell.
To connect with a provider who can diagnose or treat problems with your sense of smell, reach out to Banner Health.
