Reasons for loss of taste and smell

Much of what people call taste comes from smell, so a blocked nose can make food seem bland. A common cold may cause temporary congestion and reduced smell. COVID-19 can also present with changed or lost taste and smell, sometimes without pronounced nasal blockage. Some people notice persistent changes after the initial infection; this can occur with Long COVID. Allergic nasal swelling, smoking, certain medicines, head injury and less common nerve or brain conditions are other possibilities. A clinician considers the timing, one-sided symptoms and accompanying features rather than treating the symptom as a diagnosis.

Record whether the change is sudden or gradual, whether both sides are affected, and whether congestion, fever, cough, headache or recent infection came first. Avoid relying on smell to detect smoke, gas or spoiled food while it is reduced. Saline nasal care may ease congestion for some people; ask a pharmacist or clinician before using medicated sprays for longer than directed. Arrange assessment if the change persists, keeps returning, follows a head injury or affects eating and safety. Testing and a nasal or neurological examination may be considered.

Seek urgent help after a head injury if there is confusion, weakness, severe headache, vomiting or a seizure. Get prompt medical advice for breathing difficulty, facial swelling, severe illness, or a sudden change with other neurological symptoms. Otherwise, book a review when loss persists or interferes with nutrition or daily safety.

Could congestion, infection, a medicine or an injury explain this change? Should I test for COVID-19? Do I need an examination, follow-up or referral if it continues?