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Why does baby wake up crying?

Baby wakes up crying

Does your baby wake up crying in the night or during nap time?

When the house is quiet in the still of night it can be quite a jolt when the peace is disturbed by loud cries from your baby. 

I remember clearly when my little ones did this as babies. Both of them would wake up crying, suddenly and very loudly. 

It’s a quite anxious moment because not only are you half asleep having just been pulled from your own dreams but your baby is really wailing as if something is very badly wrong. 

But the thing is that quite often I would find that they were not awake at all, they were just crying in their sleep.

The cries would be very loud and sound very urgent, but actually if I paused for a short time they would stop just as quickly as they started. 

Baby wakes up crying

So why does your baby cry in their sleep and how can you tell whether they are just having a very vocal dream or they are actually awake and need you to pick them up? 

To understand why your baby is waking up crying then its worth understanding how their sleep is different to how older children and adults sleep. 

Baby wakes up from sleep crying

For a start they sleep for longer over a 24-hour period but in shorter bursts. 

During these short stints of sleep they spend more time on rapid eye movement (REM) sleep than we do. 

REM sleep, or “active sleep” is a lighter stage of sleep than “deep sleep”. You will be able to tell your baby is in REM sleep as their eyes will move beneath their eyelids and they may also pull a few facial expressions. This means they are dreaming. 

Your baby will spend around 16 hours each day sleeping from around three months and about half of this is REM sleep.

Babies move from REM sleep to deeper sleep in different ways to us, with each sleep cycle lasting only 60 minutes compared to an adults which is about 130 minutes long.

So what does this mean? It means as your baby moves between sleep cycles they may cry in their sleep, wake up crying or wake up out of necessity for something such as hunger. 

Between these cycles your baby may be able to settle themselves back to sleep, but most babies under six months will need some help getting back to sleep. 

Why does your baby wake up crying 

So why does your baby wake up crying? First of all they may not be awake. Wait for a minute or two to see if your baby settles down just in case they are simply dreaming or moving to a different sleep cycle. 

If the crying continues then you need to run through the main reasons why any baby cries – hunger, discomfort, separation anxiety. 

In the early weeks figuring out why your baby is crying may feel overwhelming, but it becomes easier with time to figure out what your baby needs. 

Let’s take a look at the reasons why your baby may wake up crying: 

Too hot or too cold 

A baby who is too hot or cold may have woken up because they are not comfortable.

You can check your baby’s temperature quickly by feeling their chest or back of their neck. If they feel hot or a bit cool then you can adjust the number of blankets on them. 

I thoroughly recommend getting a room thermometer so that you can check the temperature of the room before putting your baby down and before you go to sleep. 

This gives you an idea of how to dress your baby for bed. Baby sleeping bags make it much easier to keep your baby cosy at night as they cannot kick them off. 

You can’t start using sleeping bags until your baby is above 8lbs 13oz, according to the Grobag manufacturer. Always double check the age and weight limits on bedding before using them with your baby.

Grobags are sold with temperature and dressing guides to help you know how to dress your baby whatever the season.  

On a very cold night below 16C your baby may need a bodysuit, onesie and a 2.5tog sleeping bag to keep them warm. 

On a warmer night of over 21C then your baby may just need a bodysuit and lighter tog sleeping bag. 

If you choose to use blankets then I suggest using layers of light blankets. I had muslin blankets, cellular blankets and thicker blankets. 

In general I would put my babies down with a muslin blanket and cellular blanket over them. If the temperature dropped in the night I could add one more layer. 

You should always follow safer sleep guidance for your baby. This means put their feet to the end of the crib, so that they cannot wriggle under the blankets, and tuck the blankets at chest level. 

Lullaby Trust has lots of safer sleep guidance.


Hunger is going to be the most likely reason your baby wakes up in the night or from a nap. 

Newborn babies may feed every two hours as their tummies are tiny and cannot take large quantities. 

You will know your baby is crying out of hunger from the following signs:

  • Bringing their hands to their face
  • Rooting – which is where the mouth opens and closes 
  • Making sucking motions and noises
  • Sucking on their hands or fingers 

If your baby has woken for a feed in the night then try to feed them in a darkened, quiet room and try to put them down to settle them back to sleep immediately after. 

Avoid changing their nappy unless you absolutely have to do so, as this may wake them up more.  

There are lots more tips for coping with night feeds on this post. 

Separation anxiety 

A baby who wakes up crying may also be suffering from separation anxiety. 

Newborn babies particularly find it difficult to not be close to their mum. It’s partly missing the feeling of being constricted in the womb but also the smell of being close to their mother too. 

You can help your baby by swaddling them and you may like to consider co-sleeping too. 

However it’s best not to deny your baby the comfort of you picking them up, especially if they are young. Although its so tough repeatedly comforting a baby throughout the night, it is a phase that doesn’t last forever. 


Your baby may have woken because something else is causing them pain or discomfort. 

The number one culprit is usually trapped wind. Signs of this will be crying and possibly bringing their legs up to their tummy. 

Baby crying in their sleep

Picking them up and burping them will quickly alleviate this pain. 

It’s also worth checking your baby’s clothes and nappy just to check nothing is on too tight or is pinching them. 

Nappy rash can cause upset too as it may feel sore. 

Use a barrier cream such as Sudocrem for every nappy change until the rash has cleared up. Then once the rash has gone change their nappy more frequently to ensure it doesn’t come back. 

What to do when baby wakes up crying 

So if your baby does wake crying what should you do?

Pause for a minute or two before you pluck your baby up out of their cot. See if they will settle themselves back down. 

When my babies cried in their sleep this was usually a very urgent sounding cry that came out of absolutely nowhere. When they had a need, such as hunger or comfort, the crying started as a grumble then gradually moved up to crying.

If your baby is still crying then pick them up and comfort them. If your baby has not fed for some time then offer them a feed before then resettling them. 

If your baby has woken crying during a daytime nap then its best to pause for a minute before you pick them up, especially if they haven’t yet had a proper nap. 

My babies both struggled with short daytime naps in the early months. They would often wake after just 30 minutes or even less. This happens when your baby is moving into a deeper sleep cycle. 

Part of the trick here is to find the right time to put your baby down for a nap. 

If your baby is overtired they may be more restless, so try to watch out for the tired signs ahead of putting them down for a nap.

You can find out more about strategies for helping your baby’s naps over on this post. 

As with most things to do with babies, crying when they wake up is a phase that will simply end one day. 

It’s very normal for babies to wake up crying so if your baby is otherwise healthy – eating well and growing normally – then you do not need to worry. 

My best piece of advice – and its something that I apply to so much to do with babies – is to accept this is a phase and remind yourself it won’t last forever. 

Why does baby wake up crying and what to do about it

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