Phantosmia is a condition that causes you to smell things that aren’t actually there. It’s also called olfactory hallucination. The smells may always be present, or may come and go. They may be temporary or last for a long time.

Smelling smoky or burning smells — including burnt toast — is a common type of phantosmia. While smelling burnt toast in particular is not diagnostic, smelling something that isn’t there can be a sign of a more serious condition. However, there are many potential causes of smelling burnt toast.

If you smell burnt toast when there’s no toast burning nearby, see a doctor so they can rule out any serious conditions.

It’s not fully understood why some people smell things that aren’t there, such as burning toast. Research suggests that phantom smells can be caused by issues in the nose or in the brain.

Issues that begin in the nose, either in the olfactory nerves in the nose itself or in the olfactory bulb just above the nose, account for 52 to 72 percent of phantom smells.

Smelling burnt toast can also be a sign of a medical condition, including some serious conditions. Potential causes include:

Sinus infection

Chronic sinus infections can disturb your olfactory system and cause phantosmia that lasts a long time. Even just one infection can temporarily damage the olfactory system and cause you to smell things like burnt toast.

Migraines

Phantom smells are an uncommon type of migraine aura, which is a sensory disturbance just before a migraine happens. These olfactory hallucinations happen just before or during a migraine, and will usually last around 5 minutes to an hour.

Allergies

Congestion from allergies can temporarily damage your olfactory system and cause you to smell things that aren’t there, like burnt toast. Antihistamines can usually relieve congestion and improve the issue.

Nasal polyps

Nasal polyps are soft, painless, non-cancerous growths on the inside of your nose. They’re usually caused by chronic inflammation and are one of the most common causes of issues with your sense of smell. This is because they can damage your olfactory system.

Upper respiratory infection

Damage to the olfactory system after an infection is a common cause of phantosmia. This is usually temporary, but can continue for long after the infection has gone away, as the damage heals.

Dental issues

Dental issues, especially persistent dry mouth, can lead to you smelling phantom smells.

Exposure to neurotoxins

Neurotoxins are chemicals that are toxic to your nervous system. Long-term exposure to neurotoxins can alter your sense of smell. Metals like lead, nickel, and mercury are most likely to cause you to smell odors like burnt toast. Other chemicals such as chemical solvents may also cause phantosmia, but the link is less clear.

Radiation treatment for throat or brain cancer

Radiation treatment can damage healthy cells near the cancer cells it targets. Because of this, radiation for throat or brain cancer can lead to changes in smell. These changes are usually temporary and go away within several months after completing treatment.

Is smelling burnt toast a sign of a stroke?

There’s no evidence that suggests phantosmia is a sign of a stroke.

However, it’s important to be aware of the warnings signs of a stroke so that you can take quick action if one occurs. Fast action improves the odds of recovering fully after a stroke.

Stroke symptoms come on suddenly, without warning. A simple “FAST” test can help you recognize a stroke in yourself or others:

  • Face. Ask the person to smile. Look for signs of drooping on one side of the face.
  • Arms. Ask the person to raise their arms. Look for a downward drift in one arm.
  • Speech. Ask the person to repeat a phrase without slurring. For example, you could have them say “The early bird catches the worm.”
  • Time. Waste no time. Immediately call your local emergency services if you or someone you know shows signs of a stroke.
Medical emergency

If you or someone else may be having a stroke, call 911 and go to the nearest emergency room right away.

Is smelling burnt toast a symptom of a seizure?

A seizure is an abnormal brain firing. Depending on its location, a seizure could cause phantosmia. The most common type of seizure that may cause you to smell burnt toast is a temporal lobe seizure. This will cause an olfactory hallucination that is sudden and lasts for less than a few minutes.

Medical emergency

A seizure is a medical emergency. Call 911 and go to the nearest emergency room if you experience these symptoms:

  • confusion
  • sudden loss of consciousness
  • abnormal movements
  • trouble speaking or understanding speech
  • loss of urine or bowels
  • vision problems

Could it be a brain tumor?

Your olfactory complex, which is what allows your brain to process smells, is in your frontal and temporal lobe. If you have a tumor in the frontal or temporal lobe, it can distort your smell system and lead to you smelling things that aren’t there.

Parkinson’s disease

Phantosmia is a common early symptom of Parkinson’s disease. It often appears before motor issues, and therefore can be a potential diagnostic tool. However, phantosmia is less common in people with genetic Parkinson’s disease.

Mental health disorders

Auditory and visual hallucinations are the most common types of hallucinations caused by schizophrenia. But olfactory hallucinations can also occur. Phantosmia may also happen in people with severe depression.

Head injury

Even minor head injuries can disrupt your sense of smell, because it can cause issues with your senses. This may be due to an injury to the olfactory nerve or to the left frontal lobe.

Neuroblastoma

Olfactory neuroblastoma is a type of cancer that starts in the nerves that affect your sense of smell. It’s a rare type of cancer that usually occurs on the roof of your nasal cavity. This can cause issues with nasal nerves, including loss of smell and phantosmia.

Epilepsy

Epilepsy can cause strange sensations, such as smelling things that aren’t there. This usually happens during a type of seizure called a simple partial seizure. These types of seizures can progress to more serious types of seizures.

Alzheimer’s disease

People with dementia may have any type of hallucination, including phantosmia. These hallucinations usually happen in the later stages of Alzheimer’s disease and are due to brain changes from the disease.

First, a doctor will take a history of your symptoms. They’ll ask what you smell, when it happens, and how often you smell it. To help make this process easier, you can keep a log of your phantom smells before your appointment.

They’ll also take a general medical history, and ask about any recent infection or trauma, and what other symptoms you have.

Then the doctor will examine your nose, mouth, and throat for inflammation or other signs of infection. If necessary, they’ll do a nasal endoscopy, which is where they look deep into your nose with a thin tube that has a camera on the end. Then they may test your sense of smell in each nostril.

Depending on your symptoms and what the physical examination shows, a doctor may also do cognitive testing. This may include testing your memory, as well as testing you for tremors, gait issues, or other motor problems.

If tests indicate a cognitive issue, or you’ve recently had a head injury, the doctor will probably perform a CT scan or MRI to look at your brain.

If you smell burnt toast when it’s not there, you should see a doctor so they can rule out potentially serious conditions. See a doctor as soon as possible if you have specific signs of a serious condition, including:

Also see a doctor if the phantom smell interferes with your daily life.

Treatment for smelling burnt toast will depend on the cause.

If it’s caused by an infection, it will likely clear up on its own. In some cases, antibiotics may be necessary.

If the smell is caused by an underlying neurological condition, your doctor will help you find the best treatment options available.

To help reduce the smell with home remedies, you can:

  • rinse your nose with a saline solution
  • use a decongestant
  • use an anesthetic spray to numb the nerve cells in your nose

Smelling burnt toast is a common type of phantom smell. It can be a sign of a serious medical condition. If you smell burnt toast, even if the smell is only temporary or comes and goes, see a doctor for diagnosis and treatment.