What Is Phantosmia

  • Haajar Dafiri BSc (Hons), Biochemistry, University of Wolverhampton, UK
  • Tanvi Shukla Master of Pharmacy - MPHARM, Nirma University

Get health & wellness advice into your inbox

Your privacy is important to us. Any information you provide to us via this website may be placed by us on servers. If you do not agree to these placements, please do not provide the information.

Best Milk Alternative

Phantosmia, Olfactory Hallucinations, or Phantom Odors, is a sensory (olfactory) disorder that causes a person to smell odours that are not actually present in the environment (phantom odours). The odours could be pleasant (e.g. freshly baked goods) or unpleasant (e.g. faeces, rotten food, and mould).

Read on to learn about the main causes and complications of phantosmia, whether you are at risk of developing phantosmia if you have/had COVID-19, how phantosmia differs from parosmia when to see a doctor and much more!


Definition of phantosmia

Also known as Olfactory Hallucinations, phantosmia1 is a sensory (olfactory) disorder that causes a person to smell odors that are not actually present in the environment (phantom odors). The odors could be pleasant or unpleasant, and detected either frequently or constantly. 

Phantosmia vs. parosmia 

Phantosmia differs from parosmia, which causes a person to smell odours that are present in the environment in a distorted way.2 Often, this means that otherwise pleasant odours, such as freshly brewed coffee, are perceived as unpleasant odours, such as sewage or garbage. 

Importance of the sense of smell

The sense of smell is incredibly important as it not only allows us to fully experience the world around us, but also influences our food choices, appetite, taste, and mood all whilst helping protect us from danger and hazardous substances (e.g. fires and gas leaks).2  Therefore, having phantosmia and one’s sense of smell altered and disrupted can have a huge impact on overall quality of life, leading to mental disorders such as anxiety and depression as well as social isolation and anhedonia (lack of interest in activities that were otherwise enjoyable) (to name a few). 

Prevalence and incidence of phantosmia 

Phantosmia is quite uncommon, accounting for only 10-20% of cases of olfactory disorders.2

Causes of phantosmia 

Phantosmia is usually idiopathic, meaning that it occurs without a known cause.2 

However, phantosmia can sometimes occur due to certain factors including: 

  1. Neurological (brain-related) conditions 

Such as:1

  • Parkinson’s disease
  • Brain tumors
  • Traumatic brain injury
  • Stroke
  • Epilepsy
  • Alzheimer’s disease
  • Neuroblastoma
  • Migraines
  • Temporal lobe seizures 
  1. Sinus and nasal issues 

Such as:1 

  • Sinus infections 
  • Nasal polyps (benign growths in nasal passages and sinuses)
  1. Psychiatric and psychological disorders 

Such as:2

  • Anxiety
  • Depression
  • Schizophrenia 
  1. Certain medications

Such as:3

  • Antidepressants: used to treat depression 
  • Antidiabetic medications: used to treat diabetes 
  • Antihyperlipidemic agents: used to treat hyperlipidemia by lowering cholesterol levels  
  • Chemotherapeutic agents: used to treat cancer 
  • Thyroid medications: used to treat thyroid problems 
  • Antibiotics: used to treat bacterial infections 
  • Proton pump inhibitors: used to treat acid reflux and gastroesophageal reflux disease (GERD)
  1. Toxic exposure to chemicals 

Such as:1

  • Mercury 
  • Lead 

Other factors 

Ageing, hypothyroidism, smoking, allergies, colds, and dental problems (e.g. gum disease and dry mouth) may also cause phantosmia.1,2  How all these conditions, disorders, and illnesses lead to phantosmia is currently unknown. 

Interestingly, a 2021 study reported the presence of phantosmia in patients with coronavirus disease 2019 (COVID-19).4 The signs and symptoms of phantosmia were found to completely disappear once the patients recovered from the viral contagious disease, suggesting a potential role of COVID-19 in the progression and development of phantosmia. 

Signs and symptoms 

The main symptom1 of phantosmia is smelling odors that are not actually present in the environment (phantom odors). 

The odours could be: 

  1. Pleasant  

Such as:

  • Freshly baked goods and sweets
  1. Unpleasant 

These are more commonly detected and include: 

  • Faeces
  • Garbage
  • Rotten food e.g. rotten eggs 
  • Burnt food e.g. burnt toast 
  • Burning rubber
  • Mould
  • Tobacco smoke
  • Gas
  • Chemicals
  • Metal 


A healthcare provider will diagnose1 a suspected patient with phantosmia by performing a series of tests in the following order:

  1. Physical examination and medical history: the healthcare provider will examine the patient’s nose as well as ears, head, and neck. A thorough medical history check-up will also be performed to rule in or rule out certain conditions that may cause phantosmia including migraines, temporal lobe seizures, schizophrenia, and mental disorders, for example.  
  1. Diagnostic tests: these may include:1
    • Nasal endoscopy: the healthcare provider will insert a thin tube with a light and camera attached called an endoscope into the patient’s nose in order to examine nasal passages and sinuses 
    • Imaging tests e.g. computed tomography (CT)1 to scan the paranasal sinuses, and/or magnetic resonance imaging (MRI)1 to scan the brain
    • A CT scan will be helpful to rule in or rule out any nasal or sinus issues, while an MRI will identify any neurological conditions, if present.  
    • Electroencephalogram (EEG): the healthcare provider may use this device to measure the patient’s brain activity and thus determine whether the patient has any neurological conditions that may cause phantosmia, including epilepsy, Alzheimer’s disease, and traumatic brain injury

Management and treatment 


There are certain home remedies available that may help people with phantosmia manage1 their symptoms, including: 

  • Nasal irrigation: this home remedy involves rinsing the nasal passages with a neti pot1 or saline solution
  • Nasal sprays: such as oxymetazoline spray, which is especially helpful for de-blocking a stuffy nose (nasal congestion) 


The treatment1 for phantosmia is a complex process as it depends primarily on the underlying cause. 

Phantosmia usually goes away in a few weeks and does not require any treatment if it is caused by colds, allergies, or infections. 

However, if caused by neurological conditions, symptoms may linger for years, and phantosmia treatment will vary depending on the cause of brain dysfunction. For example, epilepsy may be treated using medication and/or surgery, whilst treatment for brain tumours may require chemotherapy and/or radiotherapy. 

Prevention strategies 

Phantosmia cannot be prevented because it is usually a sign or symptom of other disorders and conditions such as those described in the ‘’Causes’’ section above. 

However, the risk1 of developing phantosmia can be lowered by adopting healthy lifestyle habits such as: 

  • Avoiding and/or stopping smoking
  • Maintaining a strong immune system: to prevent colds
  • Effectively managing allergies, illnesses, or disorders: consider consulting your healthcare provider to change your medication/s if you perceive phantom odours when taking them. 
  • Optimising dental health and fixing any dental problems e.g. dry mouth or gum-related concerns 
  • Washing hands frequently and maintaining good hygiene to prevent infections

When to see a doctor  

  • See a doctor1 if you develop signs and symptoms of phantosmia
  • Symptoms of phantosmia last longer than a few weeks 
  • Your symptoms worsen 


Phantosmia is a sensory (olfactory) disorder that occurs when certain odours that are not present in the environment are perceived and detected. Patients with phantosmia often report smelling burnt odours such as burnt food (e.g. burnt toast) and burning rubber. However, although less common, fruity, musty, metallic, chemical and sweet odours have also been reported. 

Despite being uncommon, phantosmia can have a huge impact on quality of life and influence not only the sense of smell but also taste, mood, appetite, and relationships. 

Although most cases of phantosmia occur spontaneously (idiopathic), phantosmia can also be caused by: 

  • Neurological conditions e.g. migraines, and Parkinson’s disease 
  • Sinus and nasal issues e.g. sinusitis and COVID-19 
  • Psychiatric and psychological disorders e.g. anxiety and depression 
  • Certain medications e.g. antidepressants, and antibiotics 
  • Toxic exposure to chemicals e.g. lead, and mercury 

Phantosmia is currently diagnosed via physical examination and thorough medical history check-up as well as diagnostic tests, including nasal endoscopy, CT and/or MRI scans, and/or electroencephalogram (EEG). 

Treatment for phantosmia varies depending on its underlying cause. No treatment is usually required for phantosmia if it develops as a result of colds, allergies, or infections as symptoms usually vanish in a few weeks. However, neurological conditions require a more complex and tailored treatment plan, with epilepsy for example requiring medication and/or surgery and brain tumour treatment involving chemotherapy and/or radiotherapy. 

Phantosmia cannot be prevented, but its risk can be lowered by:

  • Avoiding and/or stopping smoking
  • Maintaining good hygiene and a strong immune system 
  • Effectively managing allergies, illnesses, and disorders 

See a doctor mainly if: 

  • You develop any of the signs and symptoms of phantosmia 
  • Symptoms of phantosmia worsen and last for more than a few weeks


  1. Gillette B, Reid JA, Shermetaro C. Phantosmia. Treasure Island (FL): StatPearls Publishing; 2023.
  2. Bainbridge KE, Byrd-Clark D. Prescription Medication Use and Phantom Odor Perception Among US Adults. Chemosens Percept. 2020 Oct;13(2):152-158. doi: 10.1007/s12078-019-09276-6
  3. İşlek A, Balcı MK. Phantosmia with COVID-19 Related Olfactory Dysfunction: Report of Nine Case. Indian J Otolaryngol Head Neck Surg. 2022 Oct;74(Suppl 2):2891-2893. doi: 10.1007/s12070-021-02505-z.0.

Get health & wellness advice into your inbox

Your privacy is important to us. Any information you provide to us via this website may be placed by us on servers. If you do not agree to these placements, please do not provide the information.

Best Milk Alternative
[optin-monster-inline slug="yw0fgpzdy6fjeb0bbekx"]
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.

Haajar Dafiri

Bachelor of Science with Honours – BSc (Hons), Biochemistry, University of
Wolverhampton, UK

Haajar Dafiri is a recent First Class BSc (Hons) Biochemistry graduate from the University of Wolverhampton with over 4 years of academic writing experience.
She has professional experience working in both labs and hospitals such as LabMedExpert and the NHS, respectively. Due to her ‘’outstanding undergraduate’’ academic achievements, she was awarded both the Biosciences Project Prize and the Biochemical Society Undergraduate Recognition Award.

From a young age, whenever words and science were involved, Haajar eagerly followed. Haajar particularly enjoys diving deep into intricate research articles and interpreting, analysing and communicating the scientificfindings to the general public in an easy, fun and organised manner – hence, why she joined Klarity. She hopes her unique, creative and quirky writing style will ignite the love of science in many whilst putting a smile on their faces.

my.klarity.health presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818