There was a time when people thought that sleep was simply a time when the body and brain “shut off” for a few hours each night to rest in preparation for the next day. But now scientists understand that neither the body nor the brain “shut down” when we sleep; in fact, they are often working even harder than they do during the day, undergoing processes to restore cells, process information, and improve health.
Much like the daily opening and closing of tamarind tree leaves, the human body follows a natural, (approximately) 24-hour pattern called the circadian rhythm. This rhythm is influenced by the environment (such as lightness or darkness) as well as your genetic makeup and determines your sleep patterns by releasing hormones when it’s time to sleep. Abnormalities in the circadian rhythm can lead to sleep disorders like insomnia.