This myth is true - at least partially. Our immune system in particular can make good use of the restful hours of sleep. The inhibition of cortisol, noradrenaline and adrenaline as well as the simultaneous release of growth hormones and prolactin during sleep influences our immune system. Important processes, such as wound healing or antibody formation, are thus set in motion. In view of the different diseases, sleep cannot be regarded as the sole medicine. However, it is clear that restful sleep has both a preventive and healing effect on our state of health.