Olfactory Hallucinations: When to Be Concerned About Phantom Smells

Have you ever smelled something burning when nothing’s there? Or caught a whiff of cigarette smoke, perfume, or rotting food with no source in sight? These phantom odors, while disorienting, are more common than you might think. The phenomenon is called olfactory hallucination, or phantosmia, and while it’s often harmless, it can sometimes signal something more serious.

Smell is the most emotionally charged sense, tightly wired to memory and instinct. So when it malfunctions, it can be both unsettling and significant. Understanding when phantom smells are benign and when they may require medical attention is key to protecting your health and peace of mind.

What Is an Olfactory Hallucination?

Olfactory hallucinations are smells that a person perceives without any external odor source. Unlike ordinary smells, these are generated by the brain, often without any environmental trigger.

They can be:

• Brief or persistent

• Mild or overpowering

• Pleasant, strange, or deeply unpleasant

Most commonly, people report smells such as:

• Burning rubber or toast

• Gas or smoke

• Chemicals or cleaning products

• Rotting food

• Metallic or musty scents

Some experience these smells in one nostril, others in both. They may occur spontaneously or be triggered by a specific environment or sensory input.

What Causes Olfactory Hallucinations?

Phantosmia can be caused by many factors, from relatively benign issues to severe medical conditions.

Here's a breakdown of the most common causes:

1. Nasal and Sinus Conditions

• Chronic sinus infections

• Nasal polyps

• Allergies or inflammation

These can irritate olfactory neurons or distort how smells are processed. The good news? Once the underlying issue is treated, phantom smells often disappear.

2. Neurological Disorders

More concerning causes involve the brain itself, such as:

• Migraine aura

• Temporal lobe epilepsy

• Parkinson’s disease

• Alzheimer’s disease

• Brain tumors, particularly in the frontal or temporal lobes

In some cases, a phantom smell may be one of the earliest signs of a neurodegenerative condition, long before other symptoms appear.

3. Head Trauma

Even minor head injuries can impact the olfactory bulb or pathways that process scent, resulting in distorted or phantom smells.

4. Medication and Chemical Exposure

Some medications—especially antidepressants, antibiotics, or antipsychotics—can interfere with smell perception. So can exposure to solvents, smoke, or toxins.

5. Upper Respiratory Infections and COVID-19

Post-viral smell distortions (including phantom smells) have been widely reported, particularly after COVID-19. As the olfactory nerves heal, some people develop phantosmia or parosmia (a distortion of real smells).

6. Mental Health Conditions

Olfactory hallucinations can also be linked to psychotic disorders, severe anxiety, or depression, where sensory misperceptions may accompany mood or thought disturbances.

When Should You Be Concerned?

While many cases of phantosmia are benign or temporary, you should seek medical evaluation if:

• The phantom smell is persistent or worsening

• It interferes with daily life or sleep

• It’s accompanied by other symptoms, such as:

• Headaches or seizures

• Memory loss or confusion

• Mood changes or hallucinations in other senses

• Loss of appetite or nausea triggered by the smell

• You’ve recently had a head injury

• The smell suggests something burning, chemical, or dangerous, and recurs in the absence of an actual source

A neurologist or ENT specialist (ear, nose, and throat doctor) can help determine the cause through exams, imaging (MRI/CT), or smell tests.

What Can You Do About Phantom Smells?

Treatment depends on the underlying cause. Options include:

• Nasal sprays or steroids for sinus-related phantosmia

• Anticonvulsants or migraine medication for neurological triggers

• Olfactory retraining therapy (ORT): a method using repeated exposure to essential oils (like rose, clove, lemon, eucalyptus) to help retrain the brain

• Surgery, in rare cases, for structural problems or tumors

• Psychological support or medication if the issue is anxiety- or mood-related

For those recovering from a viral infection, phantosmia may resolve on its own over weeks or months.

Coping with the Emotional Toll

Olfactory hallucinations can be profoundly disorienting, even frightening. They may lead to anxiety, isolation, or social discomfort, especially when the smells are unpleasant or intrusive. It's essential to:

• Keep a smell diary to track when and how often it occurs

• Seek reassurance from medical professionals

• Connect with support groups (online or in-person) for those with smell disorders

• Practice grounding techniques to manage stress and disconnection

Remember: you’re not imagining things—your brain is processing real sensations. The key is understanding why.

Trust Your Nose—But Know When to Ask Why

Phantom smells can be as subtle as a fleeting wisp of smoke or as persistent as a lingering chemical stench. While they’re often benign, they should never be ignored, especially if they affect your quality of life or signal other health changes.

The good news is that many causes are treatable. And even when the cause is complex, early detection often leads to better outcomes.

Because when your nose tells you something’s off—and no one else smells it—it might be your body’s way of sending a message.

And sometimes, that message is worth listening to.