What can cause loss of taste and smell?

A cold can reduce smell when swelling or mucus blocks air reaching the smell receptors, which can make food seem bland. COVID-19 may also alter taste or smell, sometimes without a prominent blocked nose. Some people notice symptoms that continue after the initial infection, including as part of Long COVID. Allergies, sinus problems, nasal polyps, head injury, smoking, dental or mouth problems and certain medicines are other possibilities. The pattern and duration help guide assessment.

Note when the change began, whether it affects one or both sides, and any congestion, fever, headache, facial pain, medication change or recent infection. Avoid smoke and strong irritants, and take care with food safety because odour changes can hide spoiled food or gas leaks. Do not stop prescribed medicine without advice. A clinician can examine your nose, mouth and nerves and decide whether further evaluation is needed.

Seek urgent help for sudden loss after a head injury, new weakness, facial drooping, confusion, severe headache or trouble speaking. Arrange a clinical review if the change persists, keeps returning, affects eating, or occurs with one-sided blockage, nosebleeds, severe facial pain or unexplained weight loss. New symptoms with fever or breathing difficulty also need prompt advice.

Ask which causes fit your timing and other symptoms, whether you need testing, and how to protect nutrition and household safety while taste or smell is reduced.