The Complete Guide to Sleep Stages: What Happens Every 90 Minutes and Why It Matters for Insomnia
Your brain doesn’t just shut down when you sleep. It cycles through distinct stages every 90 minutes, each one performing specific repair work your body can’t do while you’re awake. If you’re struggling with chronic insomnia, understanding this sleep stages guide isn’t just academic curiosity—it’s the foundation for figuring out what’s actually broken in your…