The most popular definition of "stress" is "a complex interaction between an individual and the environment" that causes some response of the body (either emotional, phsyical, or both) in accordance with an individual attribute. Stress thus involves a stressor (environmental stimulus), a stress reaction (uncomfortable bodily changes and feelings), and individual characteristics. Occupational stressors are related to the job itself and to conditions associated with the organization's structure, climate, management style, and information flow. In the case of correctional officers, job-related stressors may include inmate defiance and games, maintenance of inmate discipline, compliance with inmates' rights, overcrowded conditions, and the confinement of the jail or prison environment. Stressors associated with organizational structure and administration include lack of participation in decisionmaking, lack of positive recognition, lack of administrative support, role conflict and ambiguity, and supervisory behaviors. Considerable research indicates that occupational stress may be an important cause of the typically short lifespan and the abnormally high marital and medical problems among correctional personnel. Research also links stress to decreased productivity, decreased job satisfaction, burnout, and decreased organizational commitment. References are included in Part II in the next issue.