Key symptoms of panic disorder include panic attacks and anticipatory anxiety. Panic attacks in panic disorder are characterized by random, spontaneous, and discreet episodes of increased heart rate, palpitations, shortness of breath, increased rate of breathing, and sweating. This panic attacks can occur at any time, and can last for several minutes. You then develop anticipatory anxiety, as you worry and anticipate the next panic attack coming. Some with panic disorder go on to develop agoraphobia, which is the avoidance of public places due to the fear of having a panic attacks there, or due to help or escape may be difficult.