You’ve probably heard it before—your baby is waking up all night because they’re overtired. It’s one of the biggest buzzwords in mainstream sleep advice. Parents are constantly told that missing a nap or staying up too long will send their baby into an overtired spiral, making it impossible for them to fall asleep.

But what if I told you that’s not how sleep actually works?

What does “overtired” really mean?

Yes, babies (and adults) can get very tired. We’ve all seen our kids and babies completely losing it—crying, melting down, and struggling to cope. But mainstream sleep advice goes further, claiming that when babies cross an invisible threshold of tiredness, their bodies start fighting sleep instead of giving in to it. That’s where things get misleading.

What fatigue really does to sleep

When we look at adult sleep studies (since we can’t ethically deprive babies of sleep for research), we see something surprising: the more tired someone is, the faster they fall asleep. Fatigue doesn’t block sleep—it increases sleep pressure, helping them fall asleep more easily.

So why do some babies seem wired and unable to settle when they’re exhausted? Because of dysregulation, not overtiredness.

The real reason your baby won’t sleep

Babies fall asleep best when they feel safe, calm, and regulated. If a baby is fussy, overstimulated, or stressed, their nervous system is in overdrive—making it harder to relax into sleep.

Plus, there’s something called the wake maintenance zone—a natural period of alertness before sleep. This is when babies often get a burst of energy (think of kids getting wired and giggy before bed!). If a baby is put down too early, parents might think they’re “overtired,” when in reality, they just weren’t biologically ready for sleep yet.

What should you do when your baby seems overtired?

Instead of stressing over “overtiredness” and trying to force early bedtimes or extra naps (which can actually backfire), focus on regulation. Help your baby feel safe and calm before sleep:

• Connection and comfort—rocking, snuggles, and a predictable bedtime routine
• Tuning into their unique sleep needs instead of following rigid wake windows
• Understanding that bedtime resistance is often about emotions, not exhaustion

Fatigue doesn’t stop sleep—stress does. So let’s stop blaming “overtiredness” and start focusing on what truly helps babies sleep better: feeling calm, connected, safe and secure.

Psst… Have you seen my free mini course about why Cry It Out won’t work for your baby? It will teach you three reasons I recommend avoiding Cry It Out or Ferber methods, and what you can do instead to help nurture your baby towards better sleep! Grab the free course here