Why do we need sleep?
We need sleep to let the brain and body rest and repair. Sleep helps store memories, clear waste from the brain, support the immune system and regulate mood, hormones and appetite.
During sleep, the brain cycles through stages, including deep sleep and rapid eye movement, or REM, sleep, when most vivid dreams occur. Deep sleep helps the body repair tissues and release growth hormone, while REM sleep is important for emotional processing and learning. During sleep, the brain also strengthens and organizes memories from the day.
Research suggests that during sleep, a cleaning system in the brain, called the glymphatic system, becomes more active, helping remove waste products. Lack of sleep weakens the immune system, raises the risk of heart disease, diabetes and obesity, and affects concentration, decision-making and mood.
How much sleep?
Most adults need about 7 to 9 hours of sleep a night. Teenagers need about 8 to 10 hours, and young children even more. Regular sleep times, a dark and quiet bedroom and limiting screens before bed can help improve sleep.
Did You Know?
The longest recorded time without sleep was about 11 days, by high school student Randy Gardner in 1964. Guinness no longer recognizes such records because they are dangerous.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.