The experience of perceiving a smell, such as cinnamon, when no source is present is a sensory anomaly. This neurological phenomenon occurs when the brain registers an odor signal without external chemical stimulation. While often brief and sporadic, a persistent phantom scent can be distracting, and understanding this internal sensory perception is the first step toward finding relief.
What Is Phantosmia?
Phantosmia is the medical term for smelling an odor that is not there, considered a type of olfactory hallucination. This condition arises from a malfunction along the olfactory pathway, the complex system that processes smell from the nose to the brain. Unlike normal smelling, which involves odor molecules binding to receptors, phantosmia is generated internally. The signal for the phantom smell is essentially a false alarm, originating either in the peripheral system (the nose and olfactory nerve) or the central system (the brain’s processing centers). While many people report foul, metallic, or burnt odors, some, like those smelling cinnamon, experience a more pleasant phantom scent.
Why Are You Smelling Cinnamon?
The underlying causes that trigger this phantom smell are categorized by where the malfunction occurs in the olfactory system.
Peripheral and Central Causes
The most common origins are local issues within the nose, which affect the nerve endings directly. These peripheral causes include chronic sinus infections (sinusitis), nasal polyps, or recent head colds that have irritated the olfactory epithelium.
Other common causes relate to the central nervous system, where the brain’s ability to process or generate signals is altered. Migraine auras frequently precede or accompany headaches and can involve a brief phantom smell. Phantosmia can also occur as a type of seizure, particularly those originating in the temporal lobe. Head injuries, even minor concussions, can damage olfactory structures and result in a persistent, altered sense of smell.
Systemic Factors
A third category involves external or systemic factors, such as certain prescription medications. Specific antibiotics or antidepressants have been known to list phantosmia as a potential side effect. Exposure to environmental toxins or heavy metals can also interfere with neurological function and trigger an olfactory hallucination.
Seeking Medical Guidance
Though phantosmia often resolves on its own, a medical evaluation is recommended if the phantom smell persists for more than a few weeks or is accompanied by other symptoms. Certain “red flags” necessitate an immediate doctor’s visit, such as if the smell occurs alongside seizures, loss of consciousness, or severe headaches. These symptoms could indicate a more serious neurological origin, such as a brain lesion or tumor. The diagnostic process typically begins with a physical examination of the head and neck, along with a review of the patient’s medical history and current medications.
Diagnostic Tools
If a neurological cause is suspected, the patient may be referred for imaging tests. Diagnostic tools used to identify the cause include:
- Nasal endoscopy, which involves a thin tube with a camera, to inspect the nasal cavity for polyps or chronic infection.
- Computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain.
- Electroencephalogram (EEG) to evaluate electrical activity and rule out seizure disorders.
How Phantom Smells Are Managed
The approach to managing phantosmia depends on identifying the underlying cause. If the phantom smell is traced to a local nasal problem, such as chronic sinusitis, treatment may involve antibiotics to clear an infection or steroid nasal sprays to reduce inflammation. Simple saline nasal rinses can help clear the nasal passages and reduce nerve irritation.
When phantosmia is a symptom of a neurological condition, management focuses on treating the primary disorder. If the smell is linked to epilepsy, anti-seizure medications may be prescribed to stabilize electrical activity. If the cause is a tumor, the treatment plan involves addressing that specific medical condition.
For cases where the cause remains elusive or phantosmia is chronic, management shifts to palliative care aimed at reducing the symptom’s impact. This can include olfactory training, which involves consciously sniffing strong, familiar odors to help retrain the nervous system. In rare instances where all other treatments fail, surgical excision of the olfactory epithelium—the tissue lining the nasal cavity—may be considered as a last resort.