Common cold symptoms and loss of smell

Smell depends on air carrying scent molecules to specialised receptors high inside the nose. Cold-related swelling or mucus can block that route, so food may seem less flavourful as well. A common cold is a possible cause of reduced smell, but it is not the only one. Allergic Rhinitis, Chronic Sinusitis, and COVID-19 can also affect smell. Long COVID may be considered when smell remains altered after the initial illness has passed. Loss of smell does not by itself identify the cause.

Treat congestion gently with saline spray or drops, rest, and regular fluids. Do not insert objects into the nose or use strong chemicals to test smell. Take extra care around smoke, gas, spoiled food, and hot surfaces because reduced smell can remove warning cues; check alarms and food dates by other means. Follow local infection-control advice if you have symptoms that could fit COVID-19. Note when the change began, whether it is complete or partial, and whether nasal blockage is improving.

Seek urgent help for sudden neurological symptoms, severe headache, confusion, or breathing difficulty. Arrange a medical review if smell loss is complete, persists after other cold symptoms settle, keeps returning, follows a head injury, or occurs with one-sided blockage, nosebleeds, facial pain, or visual changes. A clinician can examine the nose and consider conditions such as Chronic Sinusitis, Allergic Rhinitis, COVID-19, or Long COVID. Do not assume persistent loss is simply a cold.

Could congestion explain my smell change? How long should I monitor it? Do I need testing or an examination for another cause?