Why do Babies Wake?

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Essentials
Before 6 months, the most common reason babies wake at night is hunger. But what if they fed just 40 minutes ago? Are they still hungry or is something else going on? From teething and temperature to growth spurts and the startle reflex, there are plenty of reasons your baby might be stirring. Let's work through them so you can figure out what your little one is telling you.
Genevieve Titov, Sleep Angel
6 min read |
26 August, 2024

Hunger

Babies have tiny stomachs that fill up quickly but also empty quickly, which is why hunger is the number one reason they wake at night. In the early weeks, health professionals often recommend waking a newborn every 2 to 4 hours for a feed if they don't wake on their own.

The good news? Milk has a natural sleep-inducing effect, so feeding your baby should help them drift back off fairly quickly, even if it's only for a short stretch. For breastfeeding mothers, feeding every 2 to 3 hours in those early days also helps encourage milk production and maintain a good supply.

As your baby grows and starts eating more during the day, night feeds can gradually be reduced. It's always worth checking with your pediatrician that your baby's weight is tracking well before making changes to their feeding schedule.

Read More: Should I wake my newborn to eat?

Temperature

Getting the temperature right for someone who can't tell you in words can be tricky. A room that's too warm or too cool can pull your baby out of sleep, so it's worth knowing the signs. For a deeper dive into finding the right balance, check out our guide to the best baby room temperature.

Signs your baby is too hot

Common signs that your baby is too warm while sleeping:

  • Sweating
  • Warm to the touch (check the back of their neck or tummy)
  • Flushed skin

Important: These signs combined with a raised temperature can also be indicators of illness. If there is no change in their temperature after adjusting their environment, seek medical advice.

To help bring your baby's temperature down, you can try:

  • Offering fluids suitable for their age
  • Changing the fabric weight of their sleepwear to suit the room temperature
  • Moving your baby to a cooler, well-ventilated room if possible

Signs your baby is too cold

You can check your baby's temperature by feeling their back or tummy, which should feel comfortably warm (hands and feet naturally run cooler, so they're not the most reliable guide).

Signs your baby might be too cold:

  • Shivering
  • Cold hands or feet
  • Fussiness or unsettled behaviour

To keep your baby comfortable, use a room thermometer and pair it with our TOG clothing guide to choose sleepwear that matches the season and room temperature.

Dreamer Tip:

Feel the back of your baby's neck or tummy rather than their hands and feet. Little hands and feet tend to feel cooler naturally and aren't always the best gauge of overall body temperature.

The startle reflex

The Moro reflex (you might know it as the "startle reflex") is one of the very first reflexes your baby is born with. You'll know it when you see it: your baby suddenly flings their arms out, stretches their legs, and pulls back in, sometimes with a cry. It can look a little alarming, but it's completely normal and involuntary. It's a sign that your baby's nervous system is developing exactly as it should.

Swaddling can help gently support the startle reflex so your baby feels secure and settled. Our Swaddle Up range is designed to let your baby sleep in their natural arms-up position while keeping them snug enough to reduce those sudden wake-ups.

Read More: All about the startle reflex and swaddling

Teething

Teething can begin as early as 3 months, with the two central incisors on the lower gums usually appearing first, followed by the upper ones popping through anywhere between 5 and 7 months. Sore gums can make your baby uncomfortable enough to wake at night, and because sucking and swallowing send extra blood flow to the swollen area, some babies become less interested in feeding too. That can mean waking from both pain and hunger at the same time.

There isn't anything much cuter than those first baby teeth though, so the sweet toothy smiles will be worth it!

Dreamer Tip:

If your baby is teething and waking more at night, try to keep your response calm and consistent. Stick with your bedtime routine as closely as you can. The disruption is temporary and having a familiar rhythm to fall back on makes it easier for everyone.

Growth spurts

Growth spurts are frequent in the first year and can commonly occur at several points:

  • 7 to 10 days after birth
  • Between 3 and 6 weeks
  • Around 3 months
  • Around 6 months
  • Around 9 months

During a growth spurt, your baby may need more sleep overall but will also need to increase their feeding across a 24-hour period (for newborns, this is often called cluster feeding). The combination of extra hunger and a changing sleep pattern means more night waking is pretty much guaranteed for a few days.

The good news is growth spurts are short-lived. They typically last a few days to a week, and then things tend to settle again. If you'd like to understand more about how these overlap with sleep regressions, our baby sleep facts guide covers the common regression ages and what to expect.

Increased motor development

This is a fun one because although it's disruptive, it means exciting new milestones are on the way! Rolling, crawling, pulling up, even waving can all disrupt your baby's sleep. Sometimes it's the increased physical movements waking them, and sometimes they just want to practise their new skills at 2am (thanks, baby).

This can be a good time to check you have the right sleepwear to match the milestone. If your baby is ready to roll, it's time to transition out of a swaddle, and once they're on the move, a sleeping bag that allows full leg movement is the way to go.

Wet diapers and diaper rash

Soiled diapers should always be changed, day or night. Whether to change a wet diaper depends on how it's affecting your baby's sleep. If it's already heavy early in the night, it's likely to keep filling and make your baby uncomfortable later, so a quick change now can save a wake-up down the track.

Diaper rash is often caused by irritation, diarrhea, teething (which can produce more stomach acid leading to looser stools), or allergies and intolerances. If rash is causing discomfort and disturbing sleep, change diapers more frequently at night until it clears up.

Separation anxiety

Somewhere around 6 to 8 months, many babies develop a new awareness that you and they are separate people. This is a completely normal cognitive milestone, but it can mean your baby suddenly protests when you leave the room or put them down at night. They may wake more frequently and need reassurance that you're still nearby.

This phase can feel intense, but it does pass. Keeping your bedtime routine consistent, offering reassurance without creating new sleep habits you'll need to undo later, and being patient with the process all help. You're not spoiling your baby by comforting them during this stage. You're building the trust that helps them feel secure enough to sleep independently over time.

Sleep environment

Sometimes the reason for waking is simpler than you'd think. A room that's too bright in the early morning, a white noise machine that switches off after 45 minutes, or a sudden sound from another room can all pull a light sleeper out of a sleep cycle.

A few things worth checking:

  • Blackout curtains or blinds to keep the room dark, especially in summer
  • Consistent white noise that runs for the full duration of sleep (not on a timer)
  • A calm, clutter-free sleep space

Our nursery setup guide has more ideas for creating a sleep-friendly room, and our guide to white noise for babies covers how to use it safely and effectively.

Your baby's current state of health

It goes without saying that sleep (yours and theirs) will generally go out the window when your baby is sick or colicky. Babies are prone to catching simple illnesses because their immune systems are still developing, and they often find it harder to feed, settle, and stay asleep when they're unwell.

Colds and ear infections

  • Besides the common cold, ear infections are also common in babies. They can be made worse during sleep when pressure builds up from mucus and fluids gathering in the ear while lying down. These infections can develop on their own or following a cold, and because sucking and swallowing cause pain, babies may feed less during the day and wake more at night from hunger as a result.

Reflux

  • Reflux (also called gastroesophageal reflux) can prevent babies from feeding well because stomach acids are pushed back up into the esophagus, causing discomfort. It can be triggered by intolerances to dairy or lactose, and is often made worse by lying flat. For this reason, babies with reflux sometimes sleep more easily when held upright (such as in a sling during the day), though it's important to always follow safe sleep guidelines for nighttime sleep.

  • It's also worth knowing that colic and reflux are sometimes confused for each other, so if your baby seems persistently uncomfortable, it's a good idea to chat with your pediatrician.

If you're concerned about your baby's feeding or sleep patterns due to illness, always check in with your healthcare professional.

Overtiredness

It might seem like keeping your baby up longer would make them sleep better, but the opposite is often true. When babies stay awake past their comfortable wake window, their bodies release cortisol (a stress hormone) which actually makes it harder for them to fall asleep and stay asleep.

Watch for tired cues like yawning, eye rubbing, and turning away from stimulation. Catching these early and getting your baby down for sleep before they tip into overtired territory can make a real difference to how long they stay asleep. Our guide to recognising overtired signs has more detail on what to look for at each age.

Key takeaways

Hunger comes first.
It's the top reason for night waking before 6 months, and it naturally reduces as daytime feeds increase.
Check their neck, not their hands.
Feel the back of baby's neck or tummy and pair a room thermometer with the right TOG sleepwear.
Milestones shake things up.
Rolling, teething, growth spurts, and separation anxiety all disrupt sleep temporarily.
The room matters.
Darkness, consistent white noise, and a comfortable temperature all support longer stretches.
Trust your instincts.
If illness is affecting sleep and something doesn't feel right, check in with your doctor.

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