Phantosmia is a condition that causes you to smell odors that aren’t actually present. When this happens, it’s sometimes called an olfactory hallucination.
The types of odors people smell vary from person to person. Some might notice the odor in just one nostril, while others have it in both. The odor may come and go, or it may be constant.
Keep reading to learn more about what causes phantosmia and how to treat it.
While people with phantosmia can notice a range of odors, there are a few odors that seem to be most common. These include:
- cigarette smoke
- burning rubber
- chemicals, such as ammonia
- something spoiled or rotten
While the most common smells associated with phantosmia tend to be undesirable, some people do report smelling sweet or pleasant odors.
While the symptoms of phantosmia can be alarming, they’re usually due to a problem in your mouth or nose rather than your brain. In fact, 52 to 72 percent of conditions affecting your sense of smell are related to a sinus issue.
Nose-related causes include:
Other common causes of phantosmia include:
- upper respiratory infections
- dental problems
- exposure to neurotoxins (substances that are toxic to the nervous system, such as lead or mercury)
- radiation treatment for throat or brain cancer
There are many less common causes of phantosmia. Because these usually involve neurological disorders and other conditions that require immediate treatment, it’s important to contact your doctor as soon as possible if you think you may have any of the following:
In some cases, odors coming from unusual sources can make it seem like you have phantosmia. These include odors from:
- dirty air vents in your home or office
- new laundry detergent
- new bedding, especially a new mattress
- new cosmetics, body wash, shampoo, or other personal care products
When you smell an unusual odor, try to note any patterns. For example, if you only notice it when you wake up in the middle of the night, it could be coming from your mattress. Keeping a log can also help you explain your symptoms to your doctor.
Diagnosing phantosmia usually involves finding out the underlying cause. Your doctor will likely start with a physical exam that focuses on your nose, ears, head, and neck. You’ll be asked about the types of odors you smell, whether you smell them in one or both nostrils, and how long the odors tend to stick around.
If your doctor suspects a nose-related cause, they may do an endoscopy, which involves using a small camera called an endoscope to get a better look at the inside of your nasal cavity.
If these exams don’t point to a specific cause, you may need an MRI scan or CT scan to rule out any neurological conditions, such as Parkinson’s disease. Your doctor might also suggest an electroencephalogram to measure the electrical activity in your brain.
Phantosmia due to a cold, sinus infection, or respiratory infection should go away on its own once the illness clears up.
Treating neurological causes of phantosmia are more complicated, and there are many options, depending on the type of condition and its location (for example, in the case of a tumor or neuroblastoma). Your doctor will help you come up with a treatment plan that works best for your condition and lifestyle.
Regardless of the underlying cause of phantosmia, there are a few things you can do for relief. These include:
- rinsing your nasal passages with a saline solution (for example, with a neti pot)
- using oxymetazoline spray to reduce nasal congestion
- using an anesthetic spray to numb your olfactory nerve cells
While phantosmia is often due to sinus problems, it can also be a symptom of a more serious neurological condition. If you notice symptoms for more than a day or two, contact your doctor to rule out any underlying causes that need treatment. They can also suggest ways to minimize your symptoms so that phantosmia doesn’t get in the way of your everyday life.