Loss of smell when sick: what to know

When the lining of the nose swells or mucus blocks the nasal passages, fewer odour molecules reach the smell-sensing area. This can happen with a common cold, allergic rhinitis, sinus inflammation, or COVID-19. Some people notice smell changes after the main illness improves, including changes that continue after COVID-19. The symptom alone cannot tell you which illness is responsible.

Rest, drink enough fluids, and avoid smoke and irritating fumes. Note whether congestion, fever, cough, facial pressure, or taste changes occur alongside the smell loss. Use visual checks for food freshness and household hazards. Saline rinsing can help some people with nasal mucus when safe water and clean equipment are used. Do not take antibiotics or put unapproved products inside the nose without advice.

Contact a clinician if smell does not begin to improve as the illness settles, if it keeps returning, or if you cannot eat and drink normally. Seek urgent care for breathing difficulty, confusion, severe headache, swelling around the eye, vision changes, or sudden weakness. A clinician can consider infection, allergy, medicines, nasal obstruction, and other explanations.

Ask which symptoms point toward a cold, allergy, sinus inflammation, or COVID-19; whether you need testing; how to manage congestion safely; and when persistent loss should be assessed by an ear, nose, and throat specialist.