What should you know about complete loss of smell?

A blocked or inflamed nose can prevent scent molecules reaching the smell receptors. Allergic rhinitis, a common cold, chronic sinusitis, and COVID-19 can all affect smell. Some people notice altered smell during recovery, including after Long COVID. Smell helps detect smoke, gas, and spoiled food, so complete loss also creates practical safety concerns. The symptom alone cannot identify its cause.

Check smoke and gas alarms, label food with dates, and ask someone else to check food freshness while smell is absent. Treat nasal symptoms only with advice suited to you; avoid inserting objects into the nose and do not overuse decongestant sprays. Arrange a review if loss began without a blocked nose, follows a head injury, lasts beyond the expected infection, or interferes with eating. A clinician can examine the nose and review medicines and nerve symptoms.

Seek urgent help after a head injury if smell loss occurs with severe headache, repeated vomiting, confusion, weakness, a seizure, or clear fluid from the nose. Get prompt medical advice for sudden loss with facial drooping, trouble speaking, or vision changes. Seek same-day advice for breathing difficulty, severe facial swelling, or a high fever with worsening facial pain.

Ask whether nasal inflammation, infection, medicine, injury, or a nerve problem is most likely in your situation. Ask how to protect food and household safety, whether smell training is suitable, and when persistent symptoms need specialist assessment.