Does a cold cause loss of smell?

Smell depends on air carrying odour molecules to a small area high inside the nose. During a cold, inflamed tissue and mucus can narrow that passage, so foods may also seem less flavoursome. Smell often returns as congestion settles, but the timing differs between people. Loss of smell can also occur with COVID-19, allergic rhinitis, chronic sinusitis, nasal polyps, head injury or certain medicines. A cold-like illness cannot be identified by smell loss alone.

Pay attention to the pattern: blocked nose, sneezing and a sore throat fit a cold or allergy, while facial pressure, thick discharge or symptoms that keep returning may need assessment. If COVID-19 is possible in your setting, follow current local testing and infection-control advice.

Rest, drink fluids and use gentle measures for congestion, such as saline nasal spray or a humidified room. Avoid putting unprescribed oils or objects inside the nose. Check with a pharmacist before using decongestant sprays or tablets, particularly if you have high blood pressure, heart disease, glaucoma, are pregnant, or take regular medicines. Take care with smoke, gas and spoiled food because reduced smell can remove useful warning signals.

Seek urgent help for breathing difficulty, swelling of the face or throat, severe headache with neck stiffness, confusion, or new neurological symptoms. Arrange a clinical review if smell loss follows a head injury, is one-sided, comes with severe facial pain or swelling, or does not improve as the cold settles. Persistent or recurrent symptoms may need an ear, nose and throat assessment.

Does my congestion fit a common cold, allergy or sinus problem? Should I test for COVID-19? Could a medicine or nasal condition be affecting smell? Which treatment is safe with my health conditions? How long should I wait before arranging a review?