Phantosmia
Phantosmia means perceiving an odor without an external source. Learn how it differs from parosmia and nose blindness, and why lasting changes merit assessment.
Updated
Phantosmia is perceiving an odor without an external odor source. The smell may seem smoky, burnt or chemical, though its character varies. It is sometimes called a phantom smell or an olfactory hallucination.
Another person not noticing the odor does not establish phantosmia. People differ in what they detect, and a source can be intermittent or difficult to locate. Do not dismiss a possible smoke or gas hazard simply because you are the only person who notices it.
The NIDCD distinguishes phantosmia from distortion of a real smell and from reduced smell detection. Changes can accompany infections, sinus problems, injury, medication effects and other conditions. Their cause requires assessment rather than a perfume test.
Note whether the experience recurs without perfume present, when it began and whether you have other symptoms. Seek medical advice for recurring or persistent phantom odors. The NHS guidance on smell changes recommends seeing a GP if smell has not returned to normal in a few weeks. Treatment depends on the cause; stronger perfume is not a way to diagnose or correct it.
- Phantosmia
- An odor perception without an external odor source. The term describes the experience, not its cause.
- Parosmia
- A real odor is present but smells distorted or unfamiliar.
- Anosmia
- Inability to detect odors. Partial reduction is called hyposmia.
- Olfactory fatigue
- A decline in noticing an odor during continued exposure. It does not mean an odor without a source is being generated.
- Smell assessment
- A clinical evaluation that may include medical history, examination and supervised smell testing.
- Qualitative and quantitative changes
- Qualitative changes concern what is perceived, as in parosmia and phantosmia. Quantitative changes concern detection, as in reduced or absent smell.