SUMMARY
Sense of smell poses an incredibly significant aspect of our life, it has been present from the beginning of our existence and its role in maintaining the well-being of our organism is non-sustainable. Olfactory system dysfunctions have a negative influence on general health status, psychological condition and quality of life. Smell detection disturbances can not only lead to loss of pleasant feelings or basic defence mechanism deficiency, but also may be symptoms of serious ongoing or commencing diseases. The authors aimed to present in this article the most important information on physiology of olfaction system, most recent methods of examination and possible causes of smell dysfunction. A systematic review of the literature concerning smell examination was conducted including both previous review articles and original papers. Smell assessment remains an enigmatic branch of medicine, qualified personnel and special equipment which would enable to fully and reliably evaluate the condition of olfactory function is still not widely available. It seems that serious consideration of patients' complaints on odour perception, directed and complete investigation of reported dysfunctions, and adequately adjusted multidisciplinar treatment would be effective according to both, quality and length of patients' life.