Sleep health requires duration, quality, and consistent timing

Most adults require between 7 and 9 hours of sleep per night. According to Giorgos K. Sakkas, a professor at the University of Thessaly, achieving healthy sleep requires a combination of duration, quality, and consistent timing.

Sleep is a fundamental requirement for cognitive clarity, energy, and safety, rather than a task to be completed only after other obligations. During sleep, the body supports essential functions including learning, memory, emotional regulation, immune function, and metabolism. Systematic sleep deprivation can impair attention, reaction speed, and decision-making, while increasing the risk of metabolic, cardiovascular, and mental health issues.

Modern scientific approaches, including a 2025 statement from the American Heart Association, emphasize that healthy sleep is not defined by a single metric. Beyond duration, factors such as continuity, timing, stability, sleep satisfaction, and daytime alertness are critical components of overall sleep health.