Psychoneuroimmunology is a new tendency in science which integrates medicine and social sciences. An interdisciplinary point of view on the etiology and treatment of many diseases fortifies the empirically holistic conception which is very old in medicine. The disease is the result of the collapse of the defensive mechanisms in stress. The nervous, hormonal and immune systems are integrated. The social environment and stress influence the individual's personality and cause diseases, frequently cause immunosuppression. Psychotherapy can "wake" up the immune system. The results of research in psychoneuroimmunology are particular significance for psychosomatic medicine since they explain in a systemic way the earlier clinical observations and scientific studies concerning the influence of stress on the health condition. Studies of the immune system conditioning and the influence of this the relaxation training on this function are very important in coping with the disease.