This can be associated with rhinitis, sinusitis or nasal polyps. It can also be caused be degeneration of the sensitive cells for the reception of smell in the nose after a severe ‘cold’ or influenza. Smell can also be affected by a head injury, certain medications and medical conditions.
Very rarely a tumour of the nerve for smell (olfactory nerve) can affect the sense of smell.
Loss of sense of smell will require assessment and investigations as appropriate.