Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Intense and potentially disabling fear is the main characteristic of panic disorder. Panic attacks occur without any warning and obvious trigger and should be distinguished from normal experience of fear and anxiety. If untreated, this type of anxiety disorder may leave a long lasting effect on the daily life, interfering with one’s ability to carry out everyday tasks. However, medics remind that effective treatments are developed to control the recurring panic attacks. Learn more about panic disorder, its causes, symptoms and treatments in this book.