Over and Under Tiredness

OVER & UNDER TIREDNESS: your sleep enemies!

Nov 16, 2021
4 min read

Overtiredness is famous. Everyone knows about it, everyone wants to avoid it with their baby (and toddler) so much so, that some of us then venture into the territory of UNDER tiredness, Overtiredness's far less famous cousin. Devastatingly, somehow we still end up with a baby who is impossible to settle or who only sleeps in short stints.


So, what are these two sleep nemesis's and how do we avoid both of them simultaneously?

How to tell if baby is overtired

Babies have a very sensitive circadian rhythm. The younger the baby, the less awake time they can handle before their system sort of goes into overload and they need to have a sleep so their overactive brain has a chance to process and catch up. This is how they grow and learn. It's incredible and terrifying how much difference even 5 minutes can make. The younger the baby, the more sensitive they are to being awake for too long between naps and this results in overtiredness. But don't get me wrong - older babies and toddlers can still certainly suffer from overtiredness too! Some babies will give very clear signs and you'll have heaps of time to get them prepared for bed so they're asleep at the right time. Some babies (like ALL of mine!) won't really show any tired signs until it's too late. Some babies will show tired signs quite early on, but this doesn't necessarily mean they're actually ready for bed (tricksters)!


If a baby/toddler is overtired, this is what it looks like:

  • crying (when you know they aren't hungry) and difficult to calm down
  • resisting settling
  • older babies will seem hyperactive or like they have a second wind
  • tantrums in toddlers
  • waking 45 minutes after bedtime at night
  • waking a lot in the night
  • waking early morning 


What is actually happening in your child's body is a hormone has built up called cortisol. An overload of this is similar to adrenaline and sort of works like caffeine in your little one's system. This is why older babies and toddlers seem suddenly so WIDE awake - it's like they've just had a shot of coffee right before bedtime. Cortisol inhibits the production and release of another hormone - melatonin - which is the one we actually need in order to settle well and stay asleep. The more overtired your baby is, the less likely they are to then settle easily. If they're overtired at bedtime in the evening, they're starting off the night on the back foot and you're pretty much guaranteed a bad night of restless sleep then an early wake the next morning.


So, you think (I definitely thought) I'll do EVERYTHING I can to avoid this horrifying situation... you whisk your baby off to bed an hour or so after they woke from their last nap... And you then spend 45 minutes trying to get them to go to sleep while all they want to do is smile at you.


This, everyone, is undertiredness. 


How to tell if baby is undertired 

Undertiredness can look very much like it's doppleganger Overtiredness. In our haste to ensure our babies don't get overtired and therefore impossible to settle, we end up trying to put them to bed too soon and they aren't quite ready to settle to sleep yet. Two personality types will appear here: the Alert Baby and the Sleepy Baby.

The Alert Baby will simply stare at you with wide open eyes the WHOLE TIME you are trying to get them to sleep, OR be crying and fighting you every step of the way. You'll be rocking, feeding, bouncing, singing (by this stage you'll also be crying), feeding again, rocking some more... You'll assume your baby is overtired because why else wouldn't they be going to sleep? Eventually your wee one will doze off, but then in a few hours time you'll have to do it all again to get them to sleep for their next nap.

The thing is, this baby wasn't tired enough to go to sleep in the first place and was simply resisting all settling attempts as a result. By the time you'd gotten them to sleep, it would have been almost 2 hours since they woke from their last nap and if you'd tried to put them down at THAT point, they would have settled much easier and in record timing.

The Sleepy Baby will go to sleep if you do anything to actively settle them. Easily. They'll probably fall asleep feeding or while you're winding them... Except they'll then wake 20/30/45 minutes later and you will have JUST made a sandwich and a cup of tea. This baby was easy to settle because rocking is nice and calming and it was within their sleep window, but this baby wasn't tired enough to have a longer sleep because they had had too little awake time and simply were not tired enough.

Across the space of a day, an undertired baby will end up either catnapping in short bursts leading to overtiredness come bedtime at night OR nap well but then be extremely difficult to get to bed at night (because they just need some awake time).

An undertired baby generally looks like this:

  • crying (even though you know they aren't hungry)
  • resisting settling
  • older babies will really protest at nap/bed time
  • toddlers will play or get out of bed constantly or be naughty
  • napping for short periods/cat napping
  • waking a lot at night
  • waking in the night and wanting to stay awake for hours on end
  • waking early morning

Suspiciously similar behaviour to overtiredness.


Which is why it can be SO tricky to get the balance right.


Both over and under tiredness lead to poor napping and/or poor nighttime sleep. This can mean a grumpy baby and frustrated parents. So we've put together some tips to help you settle your overtired or undertired baby. 

Tips for settling an overtired or undertired baby

  • Create a good bedtime routine -  Often babies can have a build-up of overtiredness as the day progresses, so their bedtime routine shouldn't be too stimulating or overly drawn-out. Find out more here
  • Foster good sleep habits such as aiming to have your baby do at least one nap a day in their bed
  • Awake times -  Sometimes even just getting the awake times right can yield amazing results without even needing to do proper "sleep training"!
  • Work on your little ones naps first - If your baby is a poor napper, they are likely reaching bedtime in the evening very overtired, meaning they'll really resist your sleep training attempts. The same can happen if your baby has too much daytime sleep, or if their last nap is for too long or too close to bedtime. They will fight going to sleep, no matter what you do, because they're under tired.

We've taken a long time formulating our Sleep Programs to harness the perfect awake times for babies at each age, allowing them to settle well and sleep better - day and night.


So if you'd like a hand to escape the over/under tiredness curse, let us take the guesswork out for you.

CLICK HERE to download your FREE Baby Sleep Journey Chart





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