Can flu cause loss of smell?

Smell depends on airflow through the upper nose as well as healthy smell receptors. Flu can cause congestion, inflammation and thick mucus, so fewer odour molecules reach that area. A weaker sense of smell can also make food seem less flavourful. Similar symptoms may occur with a common cold, allergic rhinitis or chronic sinusitis. COVID-19 is another possible cause of a sudden smell change, particularly when the loss is not explained by a blocked nose.

Rest and drink enough fluid to avoid dehydration. Saline spray or rinsing may ease nasal blockage when used according to its instructions. Avoid smoking and do not place essential oils or other substances inside the nose. Take care around smoke, spoiled food and gas appliances while smell is reduced; ask someone else to check food and alarms if needed. Record whether smell returns as the respiratory symptoms improve.

Arrange medical review if loss of smell continues after the flu-like illness, starts without congestion, becomes recurrent, or is linked with facial pain, one-sided blockage, nosebleeds or neurological symptoms. Seek urgent care for severe breathing difficulty, confusion or fainting. Persistent loss may require assessment for sinus disease, COVID-19 or Long COVID.

Does my nose need examination? Could allergies, sinusitis or COVID-19 explain the change? Are any nasal treatments suitable for me?