An understanding of how hormones and neurotransmitters impact on sleep can help you when it comes to getting your toddler to sleep.


When it comes to sleep, the key hormones are melatonin and cortisol. The levels of these change through the day, which is why it’s easier to fall asleep at certain times of day.

Cortisol is the hormone that keeps us awake and alert. It’s at its highest at 8am, dropping throughout the day. When your little one is overtired or hyped, this stress will result in cortisol being released, preventing an easy shift to sleep.

Melatonin increases in the absence of light and gets us ready to drop off to sleep.

It’s important to know this because by working with the hormones, half that bedtime battle will be won.

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To get your toddler to sleep with ease, you should help the brain release melatonin and steer clear of trying to put your child to sleep once her cortisol levels are high.

When your child’s overtired or has been stimulated for too long, she has to try to remain alert and focused. To do this, her brain releases cortisol. As cortisol keeps your tot awake, it’s not a good idea to stimulate or stress her when a sleep is due, or to allow her to become overtired in the first place.

Why does a toddler become overtired so easily?

Your little one needs very regular sleeps to process all she learns during the day. For this reason, a baby has short 'awake times'. A newborn can comfortably manage 45 minutes of stimulation or ‘awake time’ before becoming fatigued. A 6 month old can cope with close to two hours of ‘awake time’. A toddler can cope with between four and five hours of ‘awake time’.

When this ‘awake time’ draws to a close, your toddler begins to become drowsy and ready for sleep. If you settle your toddler at this time, it’s easier for her to fall asleep because the melatonin overrides the cortisol.

If you keep your toddler awake past the age-appropriate ‘awake time’, she’ll need to access hormones to encourage alertness – that means adrenaline and cortisol will be released. These 'stress' hormones aren’t helpful when it comes to settling your child to sleep, and this is why an overtired toddler fights sleep.

What are the signs of overtiredness?

Step 1 of fatigue:

When your toddler becomes overtired she may start to say “no” or become a little resistant.

Step 2 of fatigue:

If these signals are ignored, she may start to use more obvious self-soothing signals, such as sucking her thumb or looking for a dummy.

Step 3 of fatigue:

If you miss these signals, your little one may begin to show autonomic signals [responses that occurs without her conscious control], such as:

  • Hiccups
  • Sneezing
  • Sweaty palms
  • Quick breaths

Now the signs are clear – your little one’s overtired.

Final step of overtiredness:

If you miss all these signs, the probable outcomes include your toddler:

  • Experiencing busy hyperactive behaviour
  • Fighting with friends
  • Running away
  • Being clumsy
  • Fighting sleep
  • Having resistant behaviour

All of these final steps are signs of Flight, Fright and Fight - the classic response to stress hormones.

Avoiding overtiredness

The simple way to avoid overtiredness is to ensure your child is settled to sleep according to the awake times appropriate for her age.

Getting your overtired toddler to sleep

Toddlers who are overtired tend to become very active. To get her to sleep, try to:

  • Remove her from all stimulation
  • Spend time quietly in her room
  • Read a story and give her a feed on your lap (noon or evening feed)
  • Rock her til she’s drowsy
  • If she’s very fractious, sit with her until she has fallen asleep