Hay fever and loss of smell

Allergic rhinitis can swell the lining of the nose and increase mucus, making smells seem faint or absent. Reduced smell can also make food seem less flavoursome because flavour depends partly on aroma. A common cold may produce a similar blocked-nose pattern. Chronic sinusitis can cause longer-lasting congestion, facial pressure or thick discharge. COVID-19 and Long COVID are other possible causes, so the timing and accompanying symptoms matter; loss of smell alone cannot identify the cause.

Manage the nasal blockage with advice from a pharmacist or clinician, and use any nasal spray with the technique shown on its label. Limit exposure to known pollen triggers, ventilate rooms when outdoor pollen is lower, and avoid smoke. Do not put irritating substances inside the nose. While smell is reduced, check food freshness by date and appearance rather than smell, and take care around gas, smoke and spoiled food alarms.

Contact a clinician if loss of smell is sudden, lasts after nasal symptoms settle, keeps worsening, or occurs with severe headache, facial swelling, neurological symptoms or repeated nosebleeds. Follow local infection guidance if loss begins with fever, cough, sore throat or recent exposure to COVID-19. Seek urgent care for breathing difficulty or facial swelling.

Does my nasal examination fit allergy or sinus disease? Should I test for a current infection? What treatment and follow-up are appropriate if smell does not return?