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 …

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.

May 15, 2024 · About Sleep Key points Good sleep is essential for our health and emotional well-being. Getting enough sleep and good sleep quality are essential for healthy sleep. The amount of sleep …

Jul 10, 2025 · Everyone needs sleep, but about one in three American adults don’t get enough of it. The consequences of sleep deprivation are serious, so it’s worth learning why sleep matters, how it …

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 what …

6 days ago · The sleep cycle starts with three non-REM stages and one REM stage. Ideally, you repeatedly cycle through each stage. Learn how long each stage lasts.

Sleep is essential for our health. Good sleep helps your body rest, repair, and get ready for the next day. Not getting enough can lead to a higher risk of health issues. How long you sleep and the quality of it …

Dec 13, 2025 · Sleep usually requires the presence of relaxed skeletal muscles and the absence of the overt goal-directed behaviour of which the waking organism is capable. The characteristic posture …

Dec 9, 2025 · Sleep is a natural process that helps your body restore energy, supports learning and memory, and keeps you healthy. During sleep, your brain cycles through different stages of non …

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.