The diagnosis of panic disorder is made when a patient experiences recurrent panic attacks that are discrete and unexpected and followed by a month of persistent anticipatory anxiety or behavioral change. These panic attacks are characterized by a sudden crescendo of anxiety and fearfulness, in addition to the presence of at least four physical symptoms. Finally, these attacks are not secondary to a known organic factor or due to another mental disorder. However, these diagnoses are not always obvious, and a number of other psychiatric and medical disorders may mimic these conditions (Table 12–6).