Introduction Anxiety is a basic human emotion consisting of fear and uncertainty that physically appears when an individual perceives an event as being a threat to the ego or self-esteem. Anxiety is an emotional state, represented by a feeling of dread, apprehension or fear. In humans, this can be defined by description using language; in animals, it must be inferred from behavioral observations. Anxiety can, therefore, be the result of stimuli which are naturally threatening, those that have been associated with previous danger, or stimuli that are not in themselves threatening, but have become so because of a learned association between them and subsequent discomfort or threat. In some instances, such as avoiding dangerous situations, anxiety can be helpful. However, when taken to extreme, it may produce unwarranted results.