Panic disorder is a type of anxiety disorder. People with this disorder may experience such a degree of anxiety that their feelings affect their day-to-day lives. Although most people have experienced a panic attack in their lifetime, precipitated by specific events or situations, panic attacks often occur suddenly and for no apparent reason. Panic disorder affects approximately 4% of people in North America and occurs twice as often in women as in men. This disorder can occur at any age, but it appears most often in young adults. The risk of having a panic disorder increases if any of your family members have a history of this disorder, if you have been abused, if you have experienced a traumatic event, a high level of stress or adapting to major changes in your life.