Anxiety is a normal, evolutionarily beneficial, reaction to stress. It provides the “fight or flight” response to danger, increases self-awareness, motivates and keeps us alert, however these benefits often get skewed and end up mutating into a condition that ends up hindering our function. Symptoms of an anxiety disorder include: anxious feelings with seemingly no precipitating event, jittery/nervous feelings, difficulty breathing, difficulty calming down, overall feeling of hesitation and restrictedness. Generalized anxiety disorder, or GAD, is the most common anxiety disorder where typical anxiety is aggravated to the point of making normal situations nearly impossible to deal with. Posttraumatic stress disorder, panic disorder, agoraphobia, obsessive compulsive disorder, social anxiety and more also fall under the “anxiety umbrella” and refer to more acute problems stemming from an abnormal reaction to stress. Anyone can potentially suffer from one or more of these ailments, however those who have been exposed to high stress situations, trauma, or have a family history of mental disorders (particularly anxiety) are at a higher risk. The treatment for anxiety disorders comes in both therapeutic discourse (for example, psychotherapy) and in medication treatment, through some antidepressants, benzodiazepines, and others.
SOURCES:
http://www.nimh.nih.gov/health/topics/anxiety-disorders/index.shtml