Panic disorder main feature is the presence of unexpected panic attacks where the person feels intense anxiety sensations (palpitations, dizziness, etc...) and fear. In most cases, the individual experience more frightening. Another feature is Agoraphobia, that is, avoidance of several situations like going shopping, remaining at home alone, etc. The individual believes that something terrible could happen in those situations and nobody could help him/her. Because of that he/she avoids any "dangerous" place where the occurrence of a panic attack is more likely.