Why Does My Baby Wake Up At 3:00 AM?

Cute baby girl relaxing on bed

That right there might be the single most common question new parents ask.

Is it a developmental milestone? A regression? Are they getting too much sleep during the day, or not enough? Maybe they’re just hungry. Maybe they’re too hot, or too cold. Well, the truth is that it could be any of those things, and it could be a combination of several of them. What that means, and what you’re probably already aware of, is that baby’s sleep is tremendously complicated.

Their bodies and brains are rapidly going through significant changes, and by the time they’ve got one issue under control, a new one pops up to take its place. There are factors you can control, obviously. If baby’s too hot, you can turn up the AC or put a fan in the room. If they’re teething, a little Children’s Tylenol can often solve the problem, at least temporarily. But those are the simple fixes. The reason most people have such a challenging time with their babies’ sleep is because of problems that aren’t so simple, and don’t have obvious solutions.

Imagine this scenario: An 18 month old child gets plenty of fresh air and sunlight during the day, goes down easily for long, restful naps, but when bedtime rolls around, suddenly they’re full of energy and want to play. When they’re told it’s time for bed, they get upset and bedtime becomes a battle. Once they do finally get to sleep, they wake up several times at night and never sleep past 5:30 in the morning. So what’s going on? Is baby getting too much sleep during the day?

That would be the reasonable assumption, for sure. After all, if us grown-ups were to take a 3 hour nap in the afternoon, there’s a good chance we’d have a hard time falling and staying asleep that night. But the opposite is almost always the case. What baby’s demonstrating in this scenario is actually a need for more sleep, not less.

In order to understand this counterintuitive reasoning, first a little background on how this whole system of sleep works. About three hours prior to when we’re naturally prone to waking up, our bodies start secreting a hormone called cortisol, and if you’ve done some reading on your baby’s sleep prior to this, the sight of that word probably causes you to flinch a little. Cortisol is a stimulating hormone, and is also produced in times of stress in order to elevate the heart rate and stimulate the nervous system (in case, y’know, bears) but in the morning, it’s just trying to get us started. Think of it as mother nature’s caffeine.

And if cortisol is our morning cup of coffee, melatonin is our evening glass of wine. Once the sun starts to go down, our bodies recognize the onset of night and begin to produce this lovely sleep- inducing hormone, which helps us get to sleep and stay asleep until morning, when the whole process starts over again. Melatonin production is increased and starts earlier in the evening when we awaken to some nice, bright sunlight.

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