Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and …

Jun 19, 2023 · Sleep is a body process that allows your body to rest, repair and restore itself. You need sleep to function properly. Lack of sleep has links to many health issues.

Jun 11, 2026 · Sleep is more than "lights out" time. Learn what happens when you sleep and why sleep is important for your mental and physical health.

May 15, 2024 · Quality sleep means you are getting uninterrupted and refreshing sleep. Getting quality sleep is not just about how many hours you sleep, but how well you sleep.

Feb 25, 2025 · Sleep is a complex and dynamic process that affects how you function in ways scientists are now beginning to understand. This webpage describes how your need for sleep is regulated and …

Jul 25, 2025 · There are four phases of sleep, including one for rapid eye movement (REM) sleep and three that form non-REM (NREM) sleep. These stages are determined based on an analysis of brain …

What exactly does sleep do for your body and mind? Here’s what researchers know about the science of sleep—including the stages of sleep, your biological clock, health connections and more.

Jan 31, 2025 · Consider simple tips for better sleep, from setting a sleep schedule to including physical activity in your daily routine. Many factors can interfere with a good night's sleep — from work stress …

List of non-CDC websites to find more information about sleep and sleep health. By sharing information and resources, CDC raises awareness about the importance of sleep health and its effect on public …

Dec 3, 2021 · When you sleep, your body rests, recovers and rebuilds itself through four stages. Here’s how much sleep you need to feel rested.