A circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours.[1] It can refer to any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria.The term circadian comes from the Latin circa, meaning "around" (or "approximately"), and diēm, meaning "day". The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology. Processes with 24-hour oscillations are more generally called diurnal rhythms; strictly speaking, they should not be called circadian rhythms unless their endogenous nature is confirmed.Although circadian rhythms are endogenous ("built-in", self-sustained), they are adjusted (entrained) to the local environment by external cues called zeitgebers (from German, "time giver"), which include light, temperature and redox cycles. In medical science, an abnormal circadian rhythm in humans is known as circadian rhythm disorder.In 2017, the Nobel Prize in Physiology or Medicine was awarded to Jeffrey C. Hall, Michael Rosbash and Michael W. Young "for their discoveries of molecular mechanisms controlling the circadian rhythm.Top journals have been successfully publishing quality Research articles from many years and looking forward to framing up an eminent, outstanding issue with best quality research articles. This information can be published in our peer reviewed journal with impact factors and are calculated using citations not only from research articles but also review articles (which tend to receive more citations), editorials, letters, meeting abstracts, short communications, and case reports.We request you to kindly submit and publish your paper in this best journal and get global acknowledgement.