The influence of multiple primary synchronizers, also known as "zeitgebers," adjusts the circadian rhythm of sleep's cyclical pattern. The light-dark cycle is the most effective synchronizer, although socioeconomic factors like social and professional ties also matter. Regulation of the circadian rhythm is essential for maintaining human health. The disruption of circadian rhythm can raise the risk of cardiovascular disease, stroke, diabetes, obesity, cancer, and other degenerative diseases as well as the prevalence of those illnesses. The circadian rhythm of each individual is influenced by polygenic differences and environmental variables. The degree to which each person prefers the morning or the evening is referred to as Chrono type. There are signs that suggest a connection between personal Chrono type preferences and how respiratory diseases behave.
