The article has presented a review of psychophysiological approaches to consideration of the concept of “anxiety” and emotional state morphological and functional organization. There have been shown views of national and foreign scientists on the problem of determination of normal and pathological anxiety, separation of anxiety from similar emotional states, relations between the concepts “anxiety” and “alarm”, “general anxiety” and “situational anxiety”. Particular attention has been paid to the functional approach to anxiety as a mental phenomenon, characterized by a complex structure involving neuroendocrine, somato-visceral and psychological levels of human vital activity.