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Anosmia / Smell disorders Download as PDF

Anosmia / Smell disorders

What is anosmia?

Anosmia is the medical name for the loss or lack of the sense of smell. There are different medical terms for other changes in the sense of smell:

  • Hyposmia - reduced sense of smell
  • Parosmia - smells being different to what is expected
  • Phantosmia - perception of smells that are not present
  • Congenital anosmia - total inability to smell from birth

Some healthcare professionals refer to the above as "smell disorders".


What causes the loss of smell?

Sometimes it is not possible to find the cause of the sense of smell changing or being lost – in fact, a cause may not be found in up to 1 in 5 people.

However, we know the following are the most common causes:

  • Smoking
  • Viral infections (e.g., common colds, and COVID-19)
  • Nose or sinus problems (e.g., chronic rhinosinusitis, nasal polyps)
  • Medication (e.g., opiates)
  • Head trauma or head injury
  • Age – our sense of smell naturally reduces as we get older

Some medical conditions may be associated with anosmia, including Alzheimer’s disease, Parkinson’s disease, and schizophrenia.


Will I have any tests?

Your GP may initially manage your change in sense of smell. You may be asked to try a nasal spray to see if your symptoms improve.

You will be referred to an ear nose and throat (ENT) specialist in the hospital if your GP thinks this is needed. You will be examined in the ENT clinic using a thin flexible camera in your nose to look for possible causes. The ENT doctor may also do some blood tests to check for nasal allergies or organise a skin allergy test, if appropriate. In some patients, a CT or MRI scan may be booked to look for a cause.


Will I get my sense of smell back?

Depending on the cause (if found), your doctor may be able to give you an estimate of when or whether your sense of smell is likely to improve. Unfortunately, it is very hard to predict accurately.

In general, loss of sense of smell may be reversible in people who smoke. If you stop smoking, your sense of smell may well return.

Following a virus, many people will have their sense of smell return quickly, usually within a few weeks. But others may experience more long-lasting symptoms, although the chance of recovery is still good.

Patients with sinus disease or nasal polyps may find their sense of smell improves with treatment, but this is not always the case.

Increasing age, Alzheimer’s disease and Parkinson’s disease typically result in more permanent loss or a continually worsening sense of smell.

Head trauma can cause injuries to the small nerves in the nose that sense smell (called olfactory nerves), or the part of the brain that receives the signal. Sometimes this will recover (over months to years), either partially or completely. In most, the change is permanent.


Living with anosmia

Being able to smell is an important way we keep ourselves safe. It is important to make some adjustments to how you live. You should be aware of the situations where you may not be able to detect day-to-day hazards, and try to reduce these risks:

  • Gas cooking – you may not be able to smell gas leaks so check carefully that you have turned the gas off or consider changing to an electric cooker.
  • Fire – ensure your smoke alarms are functioning.
  • Personal hygiene – regular washing, dental care, and, if appropriate, diabetic foot checks.
  • Food – ensure you check the ‘best before’ date of foods as you may be unable to smell if they have gone off.

Self-help

Smell training should be performed every day for at least 2 - 3 months to improve your current sense of smell and re-learn different smells. Fifth Sense and AbScent are charities with online tools to guide you through this process.

The following supplements have not been officially proven to improve your sense of smell, but it may be worth considering as low-risk treatments for some forms of smell disorders. These can be bought over the counter or online.

  • Omega 3 supplements – take daily for 2-3 months, alongside smell training.
  • Vitamin A drops (e.g., Vitasorb) – Use four drops in each nostril once daily for 2-3 months, alongside the above advice.

Further reading

Fifth Sense: 

https://www.fifthsense.org.uk 

http://www.fifthsense.org.uk/safety 

https://www.fifthsense.org.uk/information-sheets/

 

AbScent:

https://abscent.org


 


Disclaimer: This publication is designed for the information of patients. Whilst every effort has been made to ensure accuracy, the information contained may not be comprehensive and patients should not act upon it without seeking professional advice.


 

Date Published: 06/10/2023 Review Date: 06/10/2026

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