"They're overtired." It's one of the most common things parents hear when their baby won't settle, fights naps or wakes early. And it's often given as the reason to put your baby down earlier and earlier.
In my experience, it's usually the other way round. Your baby is far more likely to be undertired than overtired.
What does "overtired" actually mean?
The idea is that if a baby stays awake too long, they become so tired that they can't fall asleep easily. It has become the go-to explanation for almost every sleep struggle, and that sends many families in the wrong direction.
The overtiredness theory isn't backed by scientific data. And past the newborn stage, I don't believe it exists at all.
In fact, the opposite is true: your baby needs to be tired to learn to put themselves to sleep. A baby with plenty of sleep pressure settles far more easily than one who has been put down too early.
When a baby is put down before they have built up enough need for sleep, they simply aren't ready. From the outside, that can look exactly like overtiredness: crying, wriggling, fighting sleep.
Signs your baby might be undertired
- Taking a long time to fall asleep, even when you've followed your usual routine
- Chatting, rolling or playing in the cot instead of settling
- Short naps, especially ones that end after a single sleep cycle
- Early morning waking
- Waking in the night and being wide awake for a long stretch
If several of these sound familiar, it's worth asking whether your baby has had enough awake time before each sleep.
Why tired signs can be misleading
Yawning, rubbing eyes and getting a bit grumpy are often treated as a signal to put your baby down straight away. But these signs can show up long before your baby is truly ready for sleep. Babies also get grumpy for all sorts of reasons: boredom, a change of scene, or simply wanting a cuddle.
Just because your baby seems a little grumpy doesn't mean they need to go down immediately. A short change of activity, some fresh air or a different room can often carry them happily through to a better time for sleep.
What about wake windows?
Wake windows can be a useful starting point, but they're a very rough guide. Two babies of the same age can need very different amounts of awake time. If your baby is regularly struggling to settle, a little more awake time is often the missing piece. My free nap cheat sheet has typical ranges for each age.
When it's worth getting help
Getting the balance of awake time and sleep right for your baby isn't always straightforward. It depends on their age, their temperament and how much sleep they need across the whole day and night.
That's exactly what I look at when I work with a family. If your little one fights every nap or wakes early and you're not sure why, book a free 15-minute call and we can talk it through.