Anosmia (loss of smell)
Anosmia is the medical term for loss of sense of smell. There are many conditions that may result in anosmia and treatment will depend on your own situation.
Worried about your condition? Talk to a GP.
Book an appointment onlineWhat causes anosmia?
There are two main reasons you might lose your sense of smell are: something is blocking scent from reaching the nerves inside your nose; or the nerves that carry smell signals to your brain are damaged. Things that can block your nose include:
- a cold, flu or sinus infection
- hay fever or other allergies
- nasal polyps (soft growths inside your nose)
- a deviated septum (when the wall between your nostrils is off-centre)
- COVID-19.
Things that can damage the nerves that carry smell signals include:
- natural ageing, which is the single biggest cause
- a head injury
- conditions such as Alzheimer's disease, Parkinson's disease or multiple sclerosis
- some medications, including certain antibiotics and antihistamines
- Smoking.
Are there different types of smell loss?
Yes. Losing your sense of smell isn't always all-or-nothing, and doctors use different terms depending on what's changed:
- Anosmia: A total loss of smell
- Hyposmia: A partial or reduced sense of smell
- Parosmia: Familiar smells seem different or unpleasant, such as coffee suddenly smelling like petrol
- Phantosmia: Smelling something, often unpleasant, that isn't actually there.
Smell loss can also come on suddenly or build up so gradually that you don't notice it happening. Some people lose it in one nostril only, which can go unnoticed unless each side is tested separately.
How is anosmia diagnosed?
Your GP or ENT (ear nose and throat) specialist will ask when your loss of smell started, whether it came on suddenly or gradually, and about any recent illnesses, injuries or changes to your medicines.
They'll examine the inside of your nose, sometimes using an endoscope (a thin tube with a camera). You may also have blood tests to check for other conditions such as thyroid or kidney problems.
If no obvious cause is found, you may be referred for a scan, such as a CT scan of your sinuses or an MRI scan of your brain.
How is anosmia treated?
Treatment depends on what's causing your anosmia. If a cause such as nasal polyps, allergy or infection is found, treating it may improve your sense of smell, though not always. If no clear cause is found, sprays, drops or tablets are unlikely to help. You can also try smell training (also called olfactory training) at home, which has been shown to help some people recover part of their sense of smell:
- Get 4 strong-smelling essential oils, usually lemon, rose, clove and eucalyptus
- Put a few drops of one oil onto a testing strip or pad, or use it straight from the bottle
- Hold it about an inch from your nose and breathe in gently and naturally for about 10 seconds, without sniffing hard
- Rest for a minute or two, then repeat with the next oil
- Do this twice a day, ideally morning and evening, for 12 weeks
It can take weeks or longer to notice a difference, and not everyone benefits, but it's considered safe and worth trying. You can also try smelling other strong scents around your home, such as spices or garden flowers.
When should I see a doctor?
See your GP if your sense of smell doesn't come back after a cold or flu has cleared up, or if it's lost for no obvious reason. You may be referred to an ENT (ear, nose and throat) specialist if the loss lasts longer than 3 months with no clear cause. Seek more urgent advice if you also have:
- neurological symptoms, such as weakness, vision changes or difficulty speaking
- a blockage or bloody discharge on one side of your nose only
- numbness or tingling in your face
- dentures that no longer fit properly.
FAQs
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What's the difference between anosmia and hyposmia?
Anosmia is a complete loss of smell, while hyposmia is a partial or reduced sense of smell. The two share many of the same causes and are often managed in similar ways.
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Can anosmia affect my ability to taste?
Yes. Your tongue can only detect sweet, sour, salty and a few other basic tastes on its own. The subtler differences in flavour come from smell, so without it, food and drink can taste bland or less enjoyable.
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How common is losing your sense of smell?
It's very common. Around 20% of people are affected by some kind of smell disorder, and most of this is linked to natural ageing. Around 1% of adults under 65 have a more significant loss of smell.
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Can I do anything to stay safe if I've lost my sense of smell?
Yes. Since you won't be able to smell smoke or gas, make sure smoke and gas alarms are mains-powered rather than battery-only, and check food packaging for use-by dates rather than relying on smell to tell if something has gone off.
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Can anosmia be a sign of something more serious, like dementia?
Occasionally. In older people, a new loss of smell has been linked to conditions such as Alzheimer's disease and Parkinson's disease, so doctors will look for other neurological signs. In most cases, though, anosmia has a much more everyday cause, such as a cold or nasal congestion.
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What is smell training and does it work?
Smell training means regularly sniffing a set of strong scents, such as lemon, rose, clove and eucalyptus, twice a day for around 12 weeks, to help your brain relearn how to process smells. It doesn't work for everyone, and it can take weeks or longer to notice a difference, but it's considered a safe technique worth trying.