Phantosmia (Olfactory Hallucinations)

What is phantosmia?

Phantosmia (pronounced “fan–TAAZ–mee–uh”) is a condition that causes you to detect smells that aren’t actually present in your environment (phantom smells). These odors may be pleasant or unpleasant, occasional or constant. Phantosmia can affect one or both nostrils.

In most cases, phantosmia isn’t a cause for concern and will go away in time. However, in rare instances, it could indicate a more serious health condition, such as Parkinson’s disease, stroke or a brain tumor.

Another name for phantosmia is olfactory hallucinations.

How common is phantosmia?

Phantosmia isn’t very common. When it comes to disorders that affect your sense of smell, phantosmia makes up 10% to 20% of cases.

What are the symptoms of phantosmia?

Phantosmia refers to any smell you detect that isn’t actually there. For some people, these odors are pleasant, like freshly baked sweets. But most people describe unpleasant smells, such as:

• Burning rubber.
• Garbage.
• Rotting food.
• Burnt toast.
• Tobacco smoke.
• Chemicals.
• A metallic odor.
• A moldy or stale smell.

Some people detect smells they can’t identify or odors they’ve never noticed before.

What are phantom smells a sign of?

Common phantosmia causes include:

• Colds.
• Sinus infections.
• Upper respiratory infections.
• Allergies.
• Nasal polyps.
• Migraines.
• Taking certain medications.
• Exposure to toxic chemicals, such as mercury or lead.
• Dental issues, such as gum disease or dry mouth.
• Smoking.

Many people also develop phantosmia after a COVID-19 infection.

Less commonly, phantosmia may be a sign of:

• Parkinson’s disease.
• Brain tumor.
• Stroke.
• Head trauma.
• Epilepsy.
• Alzheimer’s disease.
• Neuroblastoma.

How is phantosmia diagnosed?

First, a healthcare provider will need to determine why you’re having phantom smells. Determining the underlying cause will help them choose an appropriate path of treatment.

During this appointment, a provider will examine your nose, ears, head and neck. They’ll also ask questions about your symptoms, including what kinds of odors you smell, how long they last and whether you smell them in one or both nostrils.

What tests can help diagnose phantosmia?

Your healthcare provider may need to run certain tests to find out what’s causing you to smell phantom odors. These tests may include:

• Nasal endoscopy. During this procedure, a healthcare provider inserts an endoscope into your nose to look at your nasal passages and sinuses. (An endoscope is a thin, flexible tube with a light and camera.)
• Imaging tests, including CT (computed tomography) scans or MRI (magnetic resonance imaging).
• Electroencephalogram. This safe and painless test measures your brain’s activity. It can let your healthcare provider know if you have any brain-related conditions.

How is phantosmia treated?

It depends on the underlying cause. When phantosmia is a result of colds, allergies or infections, the phantom smells should stop once you recover.

Treating neurological (brain-related) cases of phantosmia is more challenging. There are different treatments depending on the exact cause. For example, people who have epilepsy may need medication or surgery. A person with a brain tumor will need chemotherapy and/or radiation therapy.

Once your healthcare provider determines the root cause of phantosmia, they’ll recommend the appropriate treatment.

Home remedies for phantosmia

People with phantosmia may find relief with these home remedies:

• Nasal irrigation. Rinse your nasal passages using a neti pot or over-the-counter saline solution.
• Nasal sprays. Use oxymetazoline spray to reduce nasal congestion. You can purchase this nasal spray over the counter.

Can I prevent phantosmia?

You can’t prevent phantosmia because it’s often a symptom of other unpreventable illnesses and conditions. However, once you find out what caused phantosmia, you can take steps to reduce your risk.

How can I lower my risk for phantosmia?

To reduce your risk of phantosmia, avoid potential triggers and make any necessary lifestyle changes:

• Stop smoking.
• Ask your healthcare provider about switching medications that could cause phantom smells.
• Keep your allergies in check.
• Seek immediate care for colds and other infections.
• Fix any existing dental issues.
• Wash your hands frequently to lower your risk of infections.

Does phantosmia ever go away?

Phantosmia is usually temporary and should go away in a few weeks. But your symptoms may linger if a neurological issue is the cause. You should see a healthcare provider if phantom smells last for more than a few weeks.

How long does phantosmia last?

The answer to this question is different for everyone. If phantosmia is a result of a cold or infection, symptoms should go away once your condition improves. But if phantosmia is a result of a neurological issue, then symptoms can linger much longer — sometimes, for years.

When should I see my healthcare provider?

If you have phantom smells that last more than three weeks, you should call a healthcare provider. In most cases, phantosmia should go away once you’ve recovered from the underlying illness.

What questions should I ask my healthcare provider?

If you or a loved one has phantosmia, here are some questions you may want to ask your healthcare provider:

• Why am I experiencing phantom smells?
• How long will this last?
• Do I need treatment for an underlying condition?
• What are some ways I can ease my symptoms?
• Do I need to see an otolaryngologist (ENT) or another healthcare specialist?

Phantosmia vs. parosmia: What’s the difference?

Phantosmia is when you detect smells that aren’t there, while parosmia refers to a distorted sense of smell. These conditions share many of the same causes. Like phantosmia, parosmia treatment depends on the underlying cause.

Is phantosmia a mental health condition?

No, but phantosmia may be a symptom of some mood disorders and mental health conditions, including schizophrenia.

A note from Cleveland Clinic

Phantosmia refers to detecting smells that aren’t really there. It’s a symptom of many common conditions, including allergies, colds and upper respiratory infections. It could also indicate a brain-related condition, including epilepsy, stroke or Alzheimer’s disease. If you have phantom smells that last longer than a few weeks, schedule an appointment with your healthcare provider. They can determine the underlying cause and recommend the appropriate treatment.