Loss of Smell and Taste

Most of what we call taste is actually smell. The tongue detects only sweet, salt, sour, bitter and savoury — everything else, all the flavour and complexity of food, comes through the nose.

That is why people who lose their sense of smell describe food as tasting of nothing, and why true loss of taste alone is uncommon while loss of smell is not.

The commonest causes are a blocked nose and a preceding viral infection, and both usually improve. Recovery can be slow — months rather than weeks — and it is often incomplete at first, with distorted smells appearing before normal ones return. That distortion is a sign of recovery, not of damage.

Smell training is the best-evidenced treatment, it is free, and most people are never told about it.

Common

• Viral infection — including COVID-19, colds and flu. Usually recovers, though it can take months
• Nasal blockage — allergic rhinitis, chronic rhinosinusitis, and nasal polyps, which are a common and treatable cause of gradual smell loss
• Smoking
• Medication — some antibiotics cause taste disturbance, and nasal sprays can too. See the list on this page
• Ageing — smell declines gradually and normally with age

Less common

• Head injury — the nerve fibres can be sheared, and recovery is variable
• Zinc or B12 deficiency
• Underactive thyroid
• Dental problems and dry mouth, which affect taste specifically
• Previous nasal surgery, or radiotherapy

Important to consider

• Nasal or sinus tumour — suggested by one-sided loss with one-sided blockage or nosebleeds
• Parkinson's disease and Alzheimer's disease — loss of smell can precede other features by years. This is not a reason to panic about a post-viral loss, but persistent unexplained smell loss with any memory or movement change deserves assessment
• Intracranial tumour, rarely

What a consultation covers

• One nostril or both — the most important question, and one people rarely think to test
• How it began — suddenly after a virus, or gradually
• Whether the nose is blocked, and whether the loss varies with the blockage
• Any nosebleeds, facial pain or one-sided symptoms
• Whether smells are absent, reduced, or distorted
• Head injury, and nasal surgery
• Your medicines
• Memory, movement, and any tremor
• Smoking
• Weight and appetite, since loss of smell commonly reduces both

What we may arrange

B12, full blood count, thyroid function, zinc and vitamin D.

Where nasal polyps or chronic sinus disease is likely, a trial of a steroid nasal spray is reasonable and often effective. ENT referral is appropriate for one-sided loss, suspected polyps, or loss persisting beyond a few months.

The limits of a video consultation

We cannot look inside your nose, which is the key examination — polyps and one-sided masses are both found that way.

One-sided loss of smell will always be referred rather than managed remotely, because it needs someone to look.

For post-viral loss with both nostrils affected and no red flags, remote assessment plus smell training is entirely reasonable.

Will my sense of smell come back?

Most post-viral loss improves, though it can take many months and may be incomplete. Recovery is gradual, and distorted smells usually appear before normal ones — which is a good sign rather than a bad one.

Does smell training actually work?

Yes — it is the best-evidenced treatment available, and it is free. Four strong smells, 20 seconds each, twice daily, for at least three months. The main obstacle is that people stop too early.

Why does everything taste of nothing?

Because most of flavour is smell. The tongue only detects five basic tastes; everything else comes through the nose. So loss of smell feels like loss of taste, and true taste loss alone is uncommon.

Things smell wrong and unpleasant now.

That is parosmia, and it is a recognised stage of recovery rather than a new problem. It is unpleasant — coffee and meat are common offenders — and it usually improves. Smell training helps.

When should I worry?

Loss in one nostril only, loss with one-sided blockage or nosebleeds, loss after a head injury, or loss with memory or movement changes. Those need assessment; two-sided post-viral loss generally does not.

Is losing smell a sign of dementia or Parkinson's?

Smell loss can precede both by years, but the overwhelming majority of smell loss is viral or nasal. It becomes relevant when the loss is unexplained and accompanied by memory, movement or tremor changes — not as an isolated finding after a cold.

Can nasal polyps cause this?

Yes, and they are a common and treatable cause of gradual smell loss. They need someone to look inside the nose, and steroid nasal sprays are often effective.