Anosmia, also known as smell blindness, is the loss of the ability to detect one or more smells. Anosmia may be temporary or permanent. It differs from hyposmia, which is a decreased sensitivity to some or all smells.

Anosmia can be due to a number of factors, including an inflammation of the nasal mucosa, blockage of nasal passages or a destruction of one temporal lobe. Inflammation is due to chronic mucosa changes in the lining of the paranasal sinus and in the middle and superior turbinates.

The term derives from the New Latin 'anosmia', based on Ancient Greek 'ἀν-' (an-) + 'ὀσμή' ('osmḗ', "smell"). Some people may be anosmic for one particular odor, a condition known as "specific anosmia". The absence of the sense of smell from birth is known as congenital anosmia.

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