Sleep and Toddler Behaviour: Why Lack Of Sleep Fuels Big Emotions - Out For The Count
- Stephanie Donaldson
- May 14
- 3 min read
Updated: Jun 5
As a parent, you have probably noticed that your toddler is much more likely to have a meltdown after a skipped nap, or a late bedtime. You're not imagining it - there's a clear and powerful connection between sleep and behaviour, particularly when it comes to emotional regulation in toddlers.
In this post, we'll explore why sleep is so vital for your toddler's mood, what happens when they don't get enough, and how consistent sleep can lead to calmer, happier days for the whole family.
Why Sleep Matters For Emotional Regulation
Sleep isn't just for rest - it's when your toddler's brain is doing some of its most important work. During sleep, particularly deep sleep and REM stages (Rapid Eye Movement), the brain:
Processes emotions
Strengthens memory
Regulates stress hormones
Restores energy needed for self-control and focus
Toddlers are still learning how to manage big emotions like frustration, disappointment and impatience. Without enough sleep, the brain struggles to regulate these feelings, leading to more frequent, intense and prolonged tantrums.
What Sleep Deprivation Looks Like In Toddlers
Sleep deprivation in toddlers doesn't always look like yawning or droopy eyelids. In fact, overtired toddlers often seem hyperactive or "wired" - a result of cortisol and adrenaline kicking in to compensate for fatigue.
Common Signs Of Sleep Deprivation Include:
Increased tantrums and emotional outbursts
Difficulty transitioning between activities
Clinginess or separation anxiety
Impulsive or aggressive behaviour
Refusal to nap or settle at bedtime (yes - being overtired can make sleep harder!)
The Science: Brain Regions Affected By Poor Sleep
Research has shown that the prefrontal cortex, the part of the brain responsible for reasoning and impulse control, is particularly affected by lack of sleep. Meanwhile, the amygdala, which handles emotional reactions like fear and anger, becomes more reactive. In short: a tired brain is a reactive brain. And toddlers already have immature nervous systems, making them more vulnerable to emotional overload.
How Much Sleep Do Toddlers Need?
Every child is different, but the general recommendation for toddlers (1-2) years is:
11-14 hours of sleep in a 24-hour period, including naps
By age 3, most toddlers still need around 10-13 hours of sleep per day.
If your child is regularly getting less than this, you ay begin to see more emotional dysregulation, even if they seem fine in the short term.
Tips To Suport Better Sleep (and Behaviour)
Stick to a Consistent Routine: Predictable nap and bedtime routines help toddlers feel secure and signal to the brain that it's time to wind down.
Watch for Sleepy Cues: Eye rubbing, zoning out, clumsiness, and irritability are all signs its time to sleep - even if they protest.
Avoid Overstimulation Before Bed: Screen time, bright lights, and loud play can delay melatonin production, making it harder to fall asleep.
Prioritise Naps: Daytime sleep supports night-time sleep and emotional regulation. Skipping naps often backfires.
Create a Sleep Friendly Environment: Use blackout blinds. white noise and a cool, quiet bedroom.
If your toddler is struggling with tantrums, emotional outbursts, or general crankiness, look at their sleep first. Sleep isn't a luxury, it's the foundation for emotional wellbeing. Helping your child get the sleep they need can dramatically improve not just their behaviour, but their overall mood, as well as the rhythm of your family life.
Need Help with Your Toddler's Sleep?
If sleep is a daily battle in your home, you're not alone - and you don't have to navigate it solo. As a certified child sleep consultant, I help families find gentle, effective solutions that work for real life.
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