Eyes, Ears, Nose & Throat

Phantom Smells: What Are They and What Do They Mean?

Something stinks! But what is it? If you've sniffed something that isn’t there, you may have experienced phantom smells—phantosmia, which could be a sign of a seizure, stroke, or brain tumor.

By Shandley McMurray • October 21, 2019

Ever smelled smoke, burnt toast, or sewage when there was no such scent around? You could be one of millions who experience phantom smells, or phantosmia, as it’s known in the medical community (more on that in the sidebar “What is Phantosmia?”).

According to a study published in JAMA Otolaryngology-Head and Neck Surgery, one in 15 Americans smells a phantom smell. Most often, these phantom smells are unpleasant (e.g., burning hair, sewage, or cigarette smoke). Sometimes they’re an indication that something more serious is going on—like a brain tumor or an epileptic seizure. The good news: Phantosmia often decreases with age, especially in women.

So, what are phantom smells? “A phantom odor is when someone perceives an odor but there is nothing in the environment that corresponds to the odor,” explains Kathleen Bainbridge, PhD, an epidemiologist in the Epidemiology and Statistics Program at the National Institutes of Health.

These phantom smells are commonly perceived as negative. The adjectives used to describe the most prevalent scents include smoky, burnt, unpleasant, spoiled, or rotten, according to Swedish researchers. Metallic smells, cooked food, and dusty or dirty odors were also noted.

On a positive note, some phantosmic people experience their phantom smell as neutral or positive (e.g., perfume or a flower). According to the study, these smells appear fleetingly, most commonly lasting for a few minutes.

What Causes Phantom Smells?

Ever wondered, “Why do I smell something that is not there?” Turns out a bunch of factors may be at play.

“The causes of phantom odor perception are not understood,” Dr. Bainbridge says. “The condition could be related to overactive odor sensing nerve cells in the nasal cavity or perhaps a malfunction in the part of the brain that understands odor signals.”

Some of the most common causes of phantom smells may include:

• Age (those over 40 are more likely to experience phantom smells)
• Abscess
• Brain tumor
• Chronic dry mouth
• Dysfunction at the olfactory nerve
• Epilepsy
• Genes (Swedish researchers have found a link between the BDNF met allele and phantosmia)
• Head injury
• Inflamed sinuses
• Medications (especially those that cause dry mouth)
• Migraine
• Parkinson’s disease
• Parosmia (a condition that involves a distorted sense of smell – smelling odors that are different than the scent involved)
• Poor overall health
• Sinusitis
• Temporal lobe seizure
• Tumors
• Upper respiratory infection

Those who are of a low socio-economic status are more likely to experience phantom smells. The reason? “People with lower socio-economic status may have health conditions that contribute to phantom odors, either directly or because of medications needed to treat their health conditions,” Dr. Bainbridge explains.

Phantom Smells Are a Symptom of…

Since our sense of taste is directly tied to our sense of smell, phantosmia can cause frustrating effects. But, Dr. Bainbridge reassures, “Phantom odors are not known to be a sign of serious underlying illness.”

As for their negative qualities, phantom smells can have an impact a person’s internal warning system. Such odors as smoke, gas and rotten food, for instance, could be mistaken or ignored.

Phantom smells also can lead to a decrease in appetite, they can turn someone off certain foods, and they may prevent the enjoyment of things (e.g., ice cream) that someone once favored. As such, phantom smells can actually result in depression, negative mood, and difficulties socializing.

Furthermore, Alan Hirsch, MD, Neurological Director of the Smell & Taste Treatment and Research Foundation, believes “phantom smells may indicate a medical or psychological condition.”

A few psychological illnesses that could cause phantom smells include:

• Delusional disorder
• Cotard’s syndrome
• Schizophrenia?
• Olfactory reference syndrome

Are Phantom Smells Common?

Quite. In her study of 7,417 U.S. adults over the age of 40, some 6.5 percent experienced phantom odors, Dr. Bainbridge found. “We found a higher prevalence in 40- to 60-year-olds compared to 60-plus-year-olds,” says Bainbridge. Her study also found that women are more likely to experience phantom smells than men.

The good news: Phantom smells seem to decrease with age.

How to Get Rid of Phantom Smells

Unfortunately, there is a lack of consensus on this important topic. That could be part of the reason why only 11 percent of those who suffer phantom smells seek professional help.

According to Hirsch, the first step to treating phantom smells is diagnosing their cause. Once you’ve determined why you’re smelling something that isn’t there, he says, you can try to treat it. “If it’s temporal lobe epilepsy, then you treat it with anticonvulsants,” Hirsch explains. “If it’s a tumor, then you cut the tumor out. If it’s sinusitis, you treat it with antibiotics.”

In some cases, the phantom smell is idiopathic, meaning it has no known cause. Essentially the brain is misinterpreting sensory stimuli. “The air is coming in through the nose and it’s being processed as a smell,” Hirsch explains. To combat this, some doctors treat patients with anticonvulsants. Here’s how they work: First, the brain views the air as a smell. Then, the anticonvulsant destabilizes “the nerve membrane [so] the nerves don’t fire off and the smell goes away.”

Other times, phantom smells result from smell loss. “When you lose your sense of smell, sometimes a phantom smell will appear and replace the smell that you no longer have,” Hirsch explains. The solution: to treat the underlying condition (i.e. smell loss) to improve phantosmia.

That said, Bainbridge claims “there are no reliable treatments for people who find phantom odors to be bothersome. Sometimes medications are tried. Sometimes, people have to cope with the symptoms until they subside.”  Confused yet?

Note: See a doctor if you’re constantly noticing a phantom smell, or if you notice a loss of smell. He or she may conduct various tests to determine the cause of your condition. Once phantom smells occur, “it may be nothing, or it may indicate an underlying disease that needs treatment,” Hirsch says.

How to Tell Whether You’re Experiencing Phantom Smells

It’s tough to know whether you’re smelling something that others aren’t. Next time you smell something strange, ask someone nearby if he or she smells the same thing.

Another test: Hold your nose and your breath to see if the smell disappears. Then, try Hirsch’s ice cream test to establish whether you’re struggling with reduced smell. Here’s how:

Step 1: Get two bowls of ice cream: one of vanilla and the other chocolate
Step 2: Taste the vanilla ice cream
Step 3: Taste the chocolate ice cream
Step 4: Determine whether you can taste a difference between the two.

“More than 90 percent of taste is smell, so almost all of chocolate is the smell, not the taste of it,” Hirsch says. “If you lose your sense of smell, it tastes the same as vanilla ice cream. So, if you can’t tell the difference between those two, that may indicate that you’ve had a a smell loss.”