Panic attacks are sudden periods of intense fear that may include palpitations, sweating, shaking, shortness of breath, numbness, or a feeling that something really bad is going to happen. The maximum degree of symptoms occurs within minutes. There may be a fear of losing control or chest pain. Panic attacks themselves are not dangerous. Panic attacks can occur due to number of disorders including panic disorder, social anxiety disorder, post traumatic stress disorder, drug use, depression, and medical problems. They can either be trigger or occur unexpectedly. Risks factors include smoking and psychological stress.