The World Health Organization has included burnout in the 11th revision of the International Classification of Diseases as an occupational phenomenon that involves “factors influencing health status or contact with health services.” Burnout is a syndrome conceptualized as resulting from chronic workplace stress that has not been successfully managed. It manifests as exhaustion, depersonalization, and reduced job satisfaction. In the United States, more than 50% of physicians have reported burnout, and their suicide rate is more than twice as high as that of the general population. Burnout in physicians is linked with increased irritability, depression, and medical errors in practice, and decreased job satisfaction, work efficacy, and concentration. Most physicians have pointed to administrative burdens outside of clinical practice as the major cause of burnout. To prevent physician burnout, regular evaluations of stress and self-awareness of one's burnout status are essential. Each physician should make proactive lifestyle changes to reduce job-related stress, such as regular exercise, seeking help, ensuring enough rest, and fostering good interpersonal relationships. Awareness and prevention of burnout are important not only for physicians’ mental health, but also for patients’ care.