Poor work organization that is the way we design jobs and work systems, and the way we manage them, can cause work stress. Excessive and otherwise unmanageable demands and pressures can be caused by poor work design, poor management and unsatisfactory working conditions. Similarly, these things can result in workers not receiving sufficient support from others or not having enough control over their work and its pressures. Research findings show that the most stressful type of work is that which values excessive demands and pressures that are not matched to workers’ knowledge and abilities, where there is little opportunity to exercise any choice or control, and where there is little support from others. The more the demands and pressures of work are matched to the knowledge and abilities of workers, the less likely they are to experience work stress. The more support workers receive from others at work, or in relation to work, the less likely they are to experience work stress. The more control workers have over their work and the way they do it and the more they participate in decisions that concern their jobs, the less likely they are to experience work stress. Most of the causes of work stress concern the way work is designed and the way in which organizations are managed. Because these aspects of work have the potential for causing harm, they are called ‘stress-related hazards’. The literature on stress generally recognizes nine categories of stress-related hazards and these are listed in Table I. One should keep in mind, though, that some of these hazards may not be universal or may not be considered harmful in specific