Anxiety is a state characterized by behavioral, cognitive, emotional and somatic components which creates unpleasant feelings that are often associated with worry or fear. It is a generalized state that is both psychological and physiological, occurring without a known triggering stimulus. This emotion differs from fear, which occurs when there is an external threat related to behaviors of avoidance or escape. Alternatively, anxiety is the result of perceived threats which seem unable to be controlled or avoided. Anxiety is typically a normal reaction to stress that prompts a person to cope with a difficult situation, but when it becomes excessive it may be classified as an anxiety disorder