How much sleep do adults need and why?

Most adults need 7–9 hours of quality sleep each night. Sleep plays a critical role in physical and mental health. It helps your brain function properly, supports emotional stability, and strengthens your immune system. Poor sleep is linked to weight gain, heart disease, and a higher risk of diabetes. Quality sleep also improves concentration, mood, and productivity. Establishing a regular sleep schedule, avoiding screens before bed, limiting caffeine, and creating a restful environment can all improve your sleep quality.