Olfaction and taste are two well known human senses. Everybody would agree that both senses are crucial in daily activities such as eating or drinking. Olfactory and gustatory information is important for our quality of life. How should we otherwise enjoy an excellent wine or taste our favorite dish? On the other hand, both senses represent an alarm system providing us with information about spoiled food or leaking gas. It is undeniable that olfactory information influences our behavior, but to what extent olfactory and taste stimuli influence our interaction with other humans and biological processes, is still a matter of debate within the field. Which importance an intact olfactory and gustatory function have, becomes often clear when theses senses are affected. The following thesis reflects the authors own clinical experience and publications as well as the thoughts, concepts, state of the art knowledge and research questions shared with national and international colleagues working in the same field of chemosensory disorders. The thesis draws a general overview of current concepts in human smell and taste disorders.