Can a common cold cause loss of smell?

Smell depends on air carrying scent molecules into the upper part of the nose. A cold can narrow those passages and coat them with mucus, so food may seem less flavourful as well. Smell commonly improves as congestion clears, but the timing varies between people.

Allergic rhinitis and chronic sinusitis can also obstruct the nose. COVID-19 may cause loss of smell and should be considered with compatible symptoms or relevant exposure. A change that persists after the respiratory illness has settled, or returns repeatedly, deserves clinical review.

Use saline nasal spray or rinse according to product instructions, drink fluids, and avoid smoke and strong irritants. Do not insert objects into the nose. Ask a pharmacist before using a decongestant, particularly if you have high blood pressure, glaucoma, pregnancy, or take regular medicines.

Take care around hazards that rely on smell: check smoke and gas alarms, label food dates, and ask someone else to check food freshness. If infection is possible, follow local testing and public-health advice.

Arrange medical advice if smell does not begin to return after congestion improves, is completely absent without a blocked nose, or is accompanied by facial pain, recurrent nasal blockage, headache, or neurological symptoms. Seek urgent help after a head injury or for sudden weakness, confusion, severe headache, or breathing difficulty.

Could congestion, allergy, sinus disease, or another infection explain the change? Should I test for COVID-19? How should I protect myself from hazards while smell is reduced?