Anxiety is an emotional response to an immediate threat and is more associated with a fight or flight reaction - either staying to fight or leaving to escape danger. It's a natural response and a necessary warning adaptation in humans - it is a normal reaction to stress and can be beneficial in some situations.
It can alert us to dangers and help us prepare and pay attention. Anxiety can become a pathologic disorder when it is excessive and uncontrollable, requires no specific external stimulus, and manifests with a wide range of physical and affective symptoms as well as changes in behaviour and cognition. In general, for a person to be diagnosed with an anxiety disorder, the fear or anxiety must be out of proportion to the situation or be age-inappropriate and hinder their ability to function normally. Anxiety has a strong anticipatory component which can lead to avoidance behaviour (of perceived triggers). The pervasive nature of anticipatory anxiety can have a negative effect on all area of an individual's life, in relationships and work performance.
Anxiety disorders are the most common of mental disorders and affect up to a third of adults at some point in their lives. Women are more likely than men to experience anxiety disorders.
Anxiety disorders include generalised anxiety disorder (GAD), social anxiety disorder (also known as social phobia), specific phobia, panic disorder, agoraphobia, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD).
But anxiety disorders are treatable and a number of effective treatments are available. Treatment helps most people lead normal productive lives.