Behind the occurrence of diseases lie certain rules. Consequently

exploring the temporal rhythm of disease is of great significance for investigating its pathogenesis

prevention and methods to lower the incidence.Ischemic stroke has annual rhythms and circadian rhythm

and tends to occur intensively in certain periods

such as winter

spring and early morning. Based on the periodic changes in physiological activities along with alternating day and night

modern medicine constantly explores the occurrence and development regularity and prevention of stroke through surveys. Based on the theory of Yin-yang and five elements and the theory of correspondence between human and nature

Chinese chronomedicine tries to understand the regularity and the peak in incidence for the disease

thereupon guiding the formulation of the principle in prevention and treatment with temporal emphasis.