Anxiety is a common human emotion and is experienced by all people at some point in life. It is characterized by a state of apprehension about a perceived threat or potentially dangerous situation. In addition, fear is a negative emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat. At mild to moderate levels, anxiety can be adaptive, motivating, and can help improve performance and attention. For example, prior to a significant life event such as an important test or presentation, some individuals may experience anxiety, which could serve as a motivator to work harder and perform better. Similarly, fear can be an adaptive response when one is confronted with a life-threatening situation, and a fight or flight response to danger is present and adaptive across many animal species. However, for some, anxiety or fear may be overwhelming, distressing, and interfere with functioning. This may require a person to seek treatment depending on the level of interference and could also result in the development of a psychiatric condition.