The human sense of smell

The sense of smell, like taste and trigeminal senses, is a chemical sense dedicated to the perception of chemical stimulations and to the generation of responses to them. Although, from an evolutionary perspective, the chemical senses are the oldest of our senses, our knowledge on the neural processing of the three chemical senses is still incomplete and has been considerably lagging behind that of our other senses. The current review aims to give an overview about human smell function. In particular we focus on the anatomy and physiology of the olfactory system, the epidemiology and the causes of olfactory loss, and on the clinical management of olfactory disorders stressing the impact of smell loss on the quality of life. Lastly, we emphasize the importance of olfaction in every day life. In our opinion, the impairment of sense of smell should be taken into serious consideration by the clinicians, as it could be the indicator of important systemic diseases or the cause of domestic accidents.