Waking up between 2 and 4 a.m. is one of the most common sleep complaints we hear from adults. In fact, a 2025 study by the National Sleep Foundation found that nearly 50% of adults experience regular middle-of-the-night awakenings.
The reassuring part? These wakings are often not random. They’re usually driven by modifiable physiologic triggers.
Here are the most common contributors.
Blood Sugar Dips
Between 2–4 a.m., your body is transitioning through lighter sleep stages. If blood sugar drops during this window, your body releases cortisol and adrenaline to bring glucose back up.
Alcohol
Alcohol initially makes you feel sleepy, but as it’s metabolized, it:
Suppresses REM sleep
Raises heart rate
Increases awakenings after 2 a.m.
Low Progesterone
Progesterone has a calming effect on the brain through GABA receptors. As levels fluctuate or decline — often starting in the 40s — sleep fragmentation becomes common.
Warm Bedroom
Core body temperature needs to drop to maintain sleep. Even a slightly warm bedroom can trigger awakenings in the early morning hours. Optimal sleep temperature for most adults is between 65–67°F.
Caffeine
Caffeine’s half-life averages 5–7 hours (and longer in some individuals). That afternoon coffee at 2 p.m. may still be circulating at 9 p.m., and subtly affecting the second half of the night.
Anxiety
If your nervous system is already on edge, the biological cortisol spike that occurs in the middle of the night can trigger your mind to take over. This can heighten and prolong wakefulness.
Blue Light Exposure
Evening blue light exposure 1-2 hours before bed has been shown to:
Delay melatonin onset
Shift circadian timing later
Reduce total melatonin amplitude
This can lead to lighter sleep in the second half of the night, which increases the chance you’ll wake between 2-4 a.m.
Practical Takeaways for Preventing Middle of the Night Wakings
Eat protein and fiber at dinner to stabilize blood sugar overnight
Avoid alcohol for 2-3 weeks and reassess your sleep
Cooler thermostat, breathable bedding, fewer heavy blankets
Cut caffeine by noon
Destress during the day
Avoid screens 1-2 hours before bed
Consider progesterone replacement therapy
If You Are Awake For > 15 Mins, Try:
Getting out of bed and going to a dim-lit area
Do a body scan, or a few rounds of deep breathing (inhale for 4 seconds, exhale for 6-8 seconds)
Return to bed only when you’re sleepy
We talk about sleep A LOT with patients. If you are interested in taking a deeper dive into your insomnia or think hormones may be contributory, schedule an appointment. We can help you get to the root cause of your sleep deprivation and on your way to better ZZZ!
