Loss of smell or taste

Category: Head, Eyes, Ears, Nose & Throat · All head & senses symptoms

What it can feel like

Loss of smell (and with it, much of taste) means scents seem faint, distorted or absent — food tastes bland because flavour is mostly smell. It commonly follows viral infections of the nose, and because smell warns us about smoke, gas and spoiled food, its loss has practical safety implications too.

Possible causes

A symptom can have many causes, and most are not serious. The lists below group conditions this symptom can be associated with — common causes first. They are possibilities to discuss with a clinician, not a diagnosis.

Common causes

Loss of smell can be associated with colds, flu and COVID-19 infections inflaming the smell lining of the nose, with nasal congestion from allergy or sinusitis, and with nasal polyps blocking airflow to the smell receptors.

Other possible causes

Persistent smell loss can be associated with head injury, long-term sinus disease, some medicines, and neurological conditions — loss of smell is an early feature of Parkinson's disease and can appear in other brain conditions.

Red flags — when to seek help promptly

Sudden smell loss after a head injury, with clear fluid dripping from the nose — urgent
Smell loss with one-sided nasal blockage or nosebleeds
Smell loss that persists beyond about three months after an infection
Smell loss with new tremor, slowness or other neurological symptoms

What a clinician may do

A clinician will examine inside the nose, ask about infections, injury and medicines, and may arrange a nasal camera examination (endoscopy) or imaging if the loss persists or is one-sided. Smell training — regular structured sniffing of strong scents — is part of rehabilitation for post-viral loss.

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Frequently asked questions

Why can't I taste food if it's my smell that's gone?

True taste — sweet, salt, sour, bitter, savoury — usually survives; what vanishes is flavour, which the brain builds mostly from smell reaching the nose from the mouth during chewing. That is why food seems cardboard-like even with a 'normal' sense of taste.

Does smell come back after a virus?

Often, yes — over weeks to months, as the smell lining regenerates. Recovery can pass through a distorted phase (parosmia) where things smell wrong, which is unpleasant but usually a sign of rewiring in progress. Persistence beyond three months earns a specialist look.

Related symptoms — Head, Eyes, Ears, Nose & Throat

Bad breath (halitosis)Bleeding gums Blocked ear feeling Blocked or runny nose Blurred vision Difficulty swallowing

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Please note: This page is educational information about a symptom. A symptom alone cannot diagnose any condition, and the causes listed here are possibilities, not a diagnosis. If you are worried about a symptom — especially one that is new, severe, getting worse or not going away — please see your own clinician, who can examine you and arrange tests. In an emergency, call your local emergency number.