If you find yourself waking up around 3am every night, you’re far from alone. A growing number of sleep experts believe they know why this happens—and how to break the cycle.

According to author and longevity advocate Dave Asprey, the most common cause is a sudden drop in blood sugar during the night. When glucose levels fall, the body releases stress hormones such as cortisol and adrenaline to bring them back up. These hormones can trigger alertness, causing many people to wake between 3am and 5am and struggle to fall asleep again.

Asprey says the brain gets the energy it needs, but the “wake-up” chemicals prevent the rest of the body from returning to restful sleep. To help stabilize blood sugar, he recommends a light bedtime snack such as raw honey, collagen, or MCT oil. These foods may offer steady energy through the night without causing a crash.

Research also shows that chronic stress can disrupt hormone levels and increase nighttime awakenings. Cortisol, often called the stress hormone, affects nearly every system in the body—from immunity to digestion—which explains why sleep can be so sensitive to emotional tension.

Poor sleep takes a heavy toll. Experts warn that ongoing sleep disruption may raise the risk of heart disease, diabetes, weight gain, and weakened immunity. Millions of adults in both the UK and US report regular sleep problems.

While waking at night doesn’t always mean insomnia, improving sleep habits can help. Limiting screens before bed, reducing caffeine, keeping the room cool, and managing stress all support smoother, deeper rest.

Better nights, many experts say, begin with steady blood sugar and calmer nerves.