0620 GMT February 21, 2019
In fact, smelling phantom smells is regularly linked to brain tumors, or even a symptom of a stroke — a serious, life-threatening medical condition that occurs when the blood supply to part of the brain is cut off, express.co.uk reported.
The medical term for imaginary odors is ‘phantosmia’, but can also be described as an ‘olfactory hallucination’.
Experts have sought to work out why the phenomenon occurs and what it could mean.
Adam Simon, GP and chief medical officer at PushDoctor.co.uk, said: “There are a number of possible causes for phantosmia, and it can be easy to jump to the scariest conclusion.
“However, a simple nasal or sinus infection is one of the first possibilities your doctor will check for.
“You might also be suffering from nasal polyps, which are small, usually harmless growths on the inside of your nose that can partially block your nasal passage and affect your sense of smell.”
High up in the nose are specialized cells which connect directly to the brain — which identifies the smell.
“Migraine sufferers may also experience temporary phantosmia as part of the aura that warns them of what’s to come,” Simon added.
A migraine aura is the collective name given to the many types of neurological symptoms that may occur just before or during a migraine headache.
Experts believe the aura is caused by brain cells causing changes to the cells in the brain, which can affect senses and perception.
However, Dr Simon said in rare cases phantosmia can be an indication of other issues.
He said: “In rare cases, it can be caused by more serious problems such as a head injury, Parkinson’s, Alzheimer’s or cancer, but the important thing is not to panic and talk to a doctor about your symptoms as soon as possible.”
He also sought to dispel the ‘burnt toast rumor’.
“There’s a popular myth that smelling burnt toast is a sign of a brain tumor, or that you’re having a stroke,” he said. “This isn’t true.
“A stroke can affect any area of your brain, so it’s possible that your sense of smell can be affected, but there’s no particular smell that you need to worry about.
“You’re actually just as likely to smell nothing at all.
“Once again, it’s much better to tell a doctor about these things than try to self-diagnose based on what your nostrils are telling you.”