Why does COVID-19 cause loss of smell?

Smell depends on air reaching specialised tissue high in the nose and on signals travelling to the brain. Swelling, congestion, and changes in the supporting cells around smell receptors can interfere with this process. Loss of Smell is a very common presentation of COVID-19, although it can also happen with colds, allergies, sinus problems, nasal growths, some medicines, and other conditions. Food may seem bland because much of flavour comes from smell, even when the tongue can still detect basic tastes.

Check that smoke alarms are working and take extra care with gas, spoiled food, and strong cleaning products because warning smells may be harder to notice. Use expiry dates and visual checks when preparing food. Keep eating regular, nourishing meals and vary texture, temperature, herbs, or seasoning if food seems uninteresting. Avoid putting irritants inside the nose. If you are congested, ask a pharmacist about options that fit your medical history.

Seek urgent help for difficulty breathing, chest pain or pressure, confusion, or trouble staying awake. Arrange a clinical review if loss of smell is persistent, is getting worse, follows a head injury, occurs on one side with ongoing blockage or bleeding, or comes with new neurological symptoms. A clinician can examine the nose and discuss whether another cause needs consideration.

Ask whether your nasal symptoms need examination, how to protect yourself at home while smell is reduced, and when follow-up would be useful.