Background and Purpose: In Persian Medicine (PM) sources, sleep is one of the important priorities for maintaining health and treating diseases. From the perspective of modern medicine, any disturbance in the circadian rhythm will alter natural fluctuations of the endocrine system. This study deals with the characteristics of a good sleep and its effects on the prevention of diseases from the perspective of PM and Modern Medicine.

Materials and Methods: This research is a review study, in which authoritative PM books also taught in PM schools (such as The Canon of Medicine) and also electronic databases such as Google Scholar, PubMed, SID and Noor software have been searched.

Results: Sleep is one of the six important principles of maintaining health from the perspective of PM. In the sources of this school, the most detailed principles of suitable sleep for different individuals are discussed. For example, children need more sleep than young adults, and women more than men. Additionally, there is more need for sleep in summer than in winter. PM also discusses the effects of poor and bad sleep. Valuable studies have been conducted in the world that have expressed the relationship between sleep problems with various physical and mental diseases such as high blood pressure, kidney problems, anxiety, depression and even infertility.

Conclusion: By studying new medical achievements in the field of sleep as well as information from PM resources, a very close and strong relationship can be found between these two perspectives. Both schools pay special attention to sleep timing. Moreover, both recognize the difference in amount of sleep needed based on individual differences, and believe in the effect of sleep on improvement of physical and psychological recovery of human being. However, in some cases, such as the characteristics of proper sleep, PM discusses much more details.