https://mayomeds.com/importance-of-sleep-for-health/
Adequate sleep (7–9 hours per night for adults) is essential for both physical and mental health. It strengthens the immune system by supporting antibody and cytokine production, reducing illness risk and helping recovery. Sleep also regulates metabolism and appetite hormones—leptin and ghrelin—helping prevent weight gain and Type 2 diabetes On the brain side, sleep enhances memory consolidation, focus, creativity, decision-making, and emotional resilience. Chronic sleep deprivation increases risks of heart disease, hypertension, stroke, obesity, diabetes, and cognitive decline. In short, quality sleep is a foundation for overall well‑being, on par with diet and exercise.
