Evaluation of olfaction.

The sense of smell is often taken for granted until it is impaired or lost. Chemosensory disorders involving a decreased, absent, or distorted sense of smell can be devastating to those who suffer them and may have an impact on an individual's health, safety, and quality of life in a number of ways. It is necessary to approach the diagnosis of chemosensory disorders in a systematic manner that may reveal reversible pathology and to provide patients with counseling that can help them accommodate their disability.