Panic attack is a form of anxiety disorder, also known as acute anxiety attack. The patient suddenly experiences chest tightness, breathlessness, palpitations, sweating, stomach discomfort, tremor, numbness of hands and feet, near-death feelings, madness, or loss of control. Each attack takes about a quarter of an hour. There may be no obvious cause. Some people may experience panic attacks due to certain places and situations, such as crowded places.