An attempt is made to define a biochemical formula for stress, as an overproduction of cortisol +/- impaired interferon response. The behavior Type A individual under stress, would exhibit elevated levels of cortisol with normal interferon response, whereas the Type C individual, would exhibit elevated levels of cortisol and impaired interferon responses. Evidence is presented that elevated levels of cortisol manufactured chronically under the affect of stress, and regardless of the type of individual affected, are a cause or the cause of chronic diseases, and not the result of same. This evidence would show that: Elevated levels of cortisol precede certain diseases, and do not follow them, when cortisol is checked out for this purpose in pre-disease conditions. When elevations of cortisol levels are induced through long-term corticosteroids therapy, in patients suffering of diseases requiring this type of treatment, conditions mimicking chronic diseases, would appear. When corticosteroids therapy would be discontinued, the "chronic diseases" mentioned above would disappear. When pharmaceuticals with potential cortisol antagonistic capabilities, were used in diseases totally unrelated, but having in common, elevated levels of cortisol, alleviation of symptoms and/or diseases would occur.