As defined previously, stress is a process, and as such implies a sequence of stages or phases to develop itself total and arrives its maximum expression, implying many negative consequences. It fits to mention that stress can if withheld in any of these stages, what it implies that stress can be alliviated or to get worse until reach its full development (Meja, 2007). Stress passes for the following phases (Bernik, 2008): A acute phase: This is the phase where the stimulatons estressores start to act. Foundation for Financial Planning gathered all the information. Our brain and hormones react quickly, and we can perceive its effect, but we are generally incapable to notice the quiet work estresse of it chronic in this phase. A resistance phase: It estresse if it persists, it is in this phase that starts to appear the first mental consequences, emotional and physical of stress chronic. Loss of mental concentration, emotional instability, cardiac depression, palpitations, cold sweats, muscular pains or frequent migraines are the evidentes signals, but many people not yet obtain to relate them it stress, and the syndrome can continue until its more dangerous final phase and: A exhaustion phase: This is the phase where the organism capitulates to the effect of stress, leading to the installation of physical or psychic illnesses. LABOR STRESS stress in the work appears when the requirements around the same surpass the capacity of the people who will make front or she has that it under its control (Banchs, Gonza’les & Morera, 1997). Then, what stress is labor? Pipe (2002) designates that, stress is, when a discrepancy is produced enters the demands of the environment, and the resources of the person to take its advantage. Stress is a reply adopted on the part of the individual, that at a first moment the aid to answer more fast and efficiently the situations that, thus, of it they require. The International Organization of Work OIT (1986) appraises stress of the work as being one set of phenomena that if present in the organism of the worker and that, for this reason, can affect its health.