The industrial physician attempts to evaluate occupational stress, the degree of tolerance on the human body, and preventing and curing the stress disorder. Most stress disorder tend to be contributed to stress from occupations. The connection between work and stress is one of many problems that the industrial physicians must explore. He must take on the responsible of trying to find avenues for therapy and preventions of stress disorders. It may be wise for physicians to conclude that all stress disorders may not come from the work environment. Many stress related diseases do not come from stress, and many of the diseases related to stress does not come from the work environment. These diseases may have shown up after an accident, infection, the aging process, or at birth. It is very difficult to evaluate the level of tolerance in the human material. It is also difficult to evaluate the level of occupational stress, since the differences in humans are so enormous. Understanding the difference between stress and tolerance is one of the greatest contributions to the industry, and one of the industrial physicians greatest challenges. In putting forth his best judgment, the industrial physicians expertise to the question of stress versus tolerance, the physician must know his patient thoroughly. He must understand the persons strengths and weakness.