Anxiety is a normal, and possibly, helpful emotion. The dictionary definition says that anxiety is a state of distress or uneasiness of mind caused by fear of danger or misfortune. Reasonable amount of anxiety can make you vigilant and prepare you to cope with challenging or frightening situation. But an excessive or out of context anxiety is considered a problem. In psychiatry, anxiety disorder is an umbrella term to describe various forms of mental disorders characterized by excessive worrying, uneasiness, apprehension and fear.