Occupational health psychology (OHP) is an interdisciplinary area of psychology that is concerned with the health and safety of workers. Houdmont and Leka noted seven major topics of occupational stress, occupational burnout, work-family conflict, workplace violence and other forms of mistreatment, safety, employment issues, and health issues. OHP emerged from two distinct applied psychology disciplines, health psychology and industrial and organizational psychology, and has been informed by other disciplines including industrial sociology, industrial engineering, economics, preventive medicine, public health, and occupational health. OHP is concerned with psychosocial factors in the work environment and the development, maintenance, and promotion of employee health and that of their families. The field focuses on factors in the workplace that can lead to injury, disease, and distress.