Why Do We Sleep?

Every night, you close your eyes and enter a completely different biological state. But *why do we actually need to sleep?* In this documentary, we explore what science has discovered about sleep: what happens to your brain during different stages of sleep, how sleep affects memory and learning, what happens to your body while you're asleep, why we dream, and what can happen when we don't get enough sleep. But there's a fascinating problem: *scientists still don't have one complete explanation for why sleep exists.* This video separates established scientific evidence from theories and unanswered questions, taking a closer look at one of the most ordinary—and mysterious—things humans do every day. 🧠 In this video: • Why humans need sleep • What happens to your brain while sleeping • REM and non-REM sleep • Sleep and memory • Sleep and the immune system • Your biological clock • What happens when you don't get enough sleep • What scientists know about dreaming • What remains unexplained about sleep 📚 Sources & Further Reading *National Institutes of Health — National Heart, Lung, and Blood Institute (NHLBI)* How Sleep Works: Sleep Phases and Stages *National Institutes of Health — National Institute of Child Health and Human Development (NICHD)* About Sleep *National Institutes of Health — NICHD* What Happens During Sleep? *PubMed — Sleep's Contribution to Memory Formation (2026)* Lutz ND, Harkotte M, Born J. Physiological Reviews. *PubMed — Sleep Restriction and Memory Formation (2024)* Crowley R, Alderman E, Javadi A-H, Tamminen J. Neuroscience & Biobehavioral Reviews. *PubMed — Recent Advances in Memory Consolidation During Sleep* All scientific claims in this video are based on information from the sources listed above. #Sleep #Science #Neuroscience #HumanBrain #SleepScience #Dreams #HumanBody #Biology #ScienceDocumentary #InterestingFacts #Psychology #DidYouKnow #Documentary