Types of Smell Loss: A Guide

Losing your sense of smell can be confusing and worrying. To make things even harder, doctors often use medical terms that may feel unfamiliar. In this guide, we explain the main types of smell loss in plain English, so you can understand what they mean and how they might affect daily life.

What Do We Mean by “Smell Loss”?

Smell loss, also called olfactory disorder, is when your sense of smell is reduced, distorted, or disappears altogether. Smell plays a bigger role than many people realise: it keeps us safe from dangers like smoke or gas leaks, helps us enjoy food, and even supports memory and emotions.

There are four main types of smell loss often described in medical settings: anosmia, hyposmia, parosmia and phantosmia. Each one affects people in different ways.

Anosmia – Complete Loss of Smell

Anosmia means you cannot smell anything at all. For some people it happens suddenly, for others it develops over time.

Common causes include:

• Viral infections such as Covid or flu
• Sinus conditions like polyps or chronic rhinosinusitis
• Head injury
• Ageing

Living with anosmia can make food seem tasteless and affect enjoyment of everyday life. It can also reduce awareness of safety hazards such as smoke or spoiled food.

Hyposmia – Reduced Ability to Smell

Hyposmia means your sense of smell is weaker than normal. You may notice that familiar scents seem faint, or you need to hold something close to detect it.

This can be temporary, for example with a blocked nose during a cold, or longer-lasting if linked to sinus disease, head injury, or neurological changes.

Hyposmia is different from anosmia because some smell function remains, but it can still have a big impact on daily life.

Parosmia – When Smells Are Distorted

Parosmia is when smells are changed or distorted. Coffee might smell burnt, meat could smell rotten, or toothpaste may trigger a foul taste.

Although parosmia can be very distressing, it is often a sign that the olfactory system is trying to repair itself. Many people experience parosmia as part of recovery after illness.

Common coping tips include:

• Avoiding known triggers
• Eating foods that are bland or cold
• Focusing on texture and temperature instead of flavour

Phantosmia – Smelling Things That Aren’t There

Phantosmia means smelling odours that do not exist in your environment. These phantom smells are often described as smoke, burning, or chemical scents.

Phantosmia can happen on its own or alongside other smell disorders. While usually harmless, it can sometimes point to an underlying medical issue. It is worth seeking medical advice if phantom smells are severe or persistent. See the NHS guide to loss of smell for more information.

Why Do Smell Disorders Happen?

The sense of smell relies on signals travelling from the nose to the brain. If this pathway is disrupted, smell can change or disappear.

Causes of smell disorders include:

• Viral infections such as Covid or flu
• Sinus conditions and nasal polyps
• Neurological conditions such as Parkinson’s or Alzheimer’s
• Head injury
• Ageing

What to Do If You Have a Loss of Sense of Smell

If you notice a sudden or unexplained loss of sense of smell, speak to your GP or ENT specialist. Clear communication helps them understand your experience, and keeping a smell diary can be useful.

There are also steps you can take at home:

• Practise smell training with a kit — an evidence-based way to support recovery
• Put extra safety measures in place, such as smoke alarms and food date checks
• Read more about recovery in our article on Covid Smell Loss Recovery
• Learn how the brain processes smell in Your Brain’s Smell Map Explained
• Explore community support through the CKOS Network
• Pay attention to wellbeing, since smell loss can affect mood and mental health

Frequently Asked Questions

Is smell loss permanent?
Not always. Many people recover fully, especially after viral infections, though recovery can take months or even years.

Does parosmia mean I am recovering?
Often yes. Parosmia is commonly part of the recovery process, though it can feel unpleasant and disruptive.

Should I see a doctor if I lose my sense of smell?
Yes, whatever type of smell loss you’re experience – particularly if the loss is sudden or unexplained. A GP or ENT specialist can rule out other causes and advise on next steps.

Can smell training really help?
Research shows that repeated smell training supports the brain’s ability to re-learn smells, and it is currently one of the most recommended recovery tools.