Why Do Babies Cry In Their Sleep? The Science Behind It

Why Do Babies Cry In Their Sleep? The Science Behind It

Just when you feel like your baby is sound asleep in their room, you hear them crying like a banshee, but when you check up on them, you find them sleeping in their tiny crib, like an angel.

No, you’re not going crazy, and yes, babies do cry in their sleep. All this crying and screaming while sleeping too? Yes! It is not uncommon for newborns to cry in their sleep.

Most babies cry in their sleep because of their sleep patterns. For most newborns, their sleep patterns alternate between two phases, non-REM (rapid eye movement) sleep and REM sleep. The latter is a lighter phase and involves dreams and might involve some tears. Sniffling and crying might occur during REM sleep, in which their eyes might flutter, and their limbs might twitch or move. Try to keep your hands off the baby, even if the urge to cuddle is too strong, it’s best to wait and watch as your baby fights off their crying.

To appease your curiosity or to help you deal with your crying baby, we’ve listed all that you need to know about what leads to babies crying in their sleep, and how to soothe these little ones.

Why Do Babies Cry In Their Sleep?

Hearing your little one crying, rushing to only find them sleeping multiple times is exhausting for most parents. And we sure know it’s not easy to see your baby cry, so we’ve enlisted some common reasons why they cry in their sleep.

Most Common Causes Of Babies Crying In Their Sleep

Here are some reasons why most babies cry while they sleep, but keep an eye out for any red flags that might prompt a doctor’s appointment.

Short Sleep Cycles

You’ve surely noticed how newborn sleep patterns are quite different from those

of us adults. They sleep soundly for long periods throughout the day, but as they grow older, they slowly get into a regular sleep pattern and their sleep cycles start to look like ours.

During this infamous light sleep phase, also referred to as Rapid Eye Movement (REM) sleep, your munchkin might twitch or even move their limbs, and you might see their eyes moving beneath their closed eyelids.

As your little one transition from one sleep cycle to another, they pass through the REM sleep phase, during which they might fleetingly wake up and cry.

You might find them stretching, stirring, or even briefly awakening during the light sleep phase, so try to let them soothe themselves to sleep.

Teething Pain Or Discomfort

Teething isn’t a walk in the park and surely does cause discomfort! This little nightmare might crawl up when you least expect it and ruin your baby’s sleep.

You might notice slight whimpering or even crying while your baby welcomes their new set of teeth! Other bodily pains might also end up disturbing sleep, and due to their growing bodies, they might become more sensitive and fussier.

If your wee one is having a lot of trouble sleeping, check in with your pediatrician to help your baby deal with the teething pain or address any underlying medical condition.

Sleep Environment

You might find your baby crying in their sleep due to the sleep environment. Try to keep tabs on whether the room is too hot for the baby, if they are bright lights in the hallway, or if there’s something in their crib that’s bothering them.

If your baby has been gassy and passing hard stools, you might need to book an appointment with a doctor.

Over Weariness

We sure are familiar with the fact that a tired baby is a fussy baby, and such babies usually cry in their sleep. Overtiredness might result from longer waking periods or fewer sleeping hours throughout the day.

Though counter-instinctive, this might trigger the release of hormones like cortisol in your baby’s system, making it more difficult for your baby to fall asleep at night. This fatigue-fighting hormone might be the culprit behind those sleepless fussy nights, eventually causing sleep regression in your baby.


You might expect your little one’s tummy to digest the milk they’ve just had slowly, but that is surely not the case! Most children digest milk quite quickly, and they might need to be fed every few hours.

To fulfill your little one’s late-night cravings, you might need to dream-feed them if you find them crying in their sleep at night. You can dream-feed them while they sleep or even when they are half asleep.

Night Terrors

Though not the same, your little one might experience both night terrors and nightmares if they are old enough to dream. Older babies, mostly 2 years or older, might experience bad dreams during the later stages of sleep cycles, while night terrors are common in the early phases of deep sleep, the non-REM sleep stage.

But both of these are uncommon among newborns, as they do not experience dreams as we do, so if your baby is too young, this might not be the reason behind their wails at night.

Separation Anxiety

Maybe your little one is too young for you to start sleep training or if your baby has trouble sleeping without you, they might be dealing with separation anxiety.

You might find them clingy throughout the day, and even more at night! They can’t just seem to let you move out of their sight! Try to be slow with sleep and be patient.

The Startle Reflex

Loud voice sure does startle us adults, but more so it activates the startle reflex in these little children, leaving them stunned and crying in their sleep.

It might take some time, as your baby’s nervous system is unlearning its innate ways, so these sudden noises could result in rampant crying at night.

Sudden noises or movements might startle your sweet baby because their newborn reflexes are in full swing. This might trigger your baby, causing them to cry in their sleep or waking up in the middle of the night.

Sleep Regression

Mental leaps might leave your little one preoccupied, and they might end up staying up for late hours at night. This could cause sleep regressions.

Most children don’t experience such disruption in sleep, but some go through sleep regression multiple times during the first few months to even 2 years of life. This could be during nap transition or separation anxiety.

Is My Baby Having A Nightmare?

Seeing your baby smile while they’re sleeping might have you thinking if your baby dreams at night. Straightforwardly, newborns do not dream, but older babies might experience good as well as bad dreams.

With a whole new world for them to explore beyond their crib, these little ones come across many emotions and even develop fears, stemming from those haunting dreams.

Most children experience this after they’ve reached the benchmark of 24 months, but the most common ages to experience such nightmares range from 3-6 years.

If your baby is younger and they have trouble staying asleep or cries in their sleep, you might consult a doctor to see if there’s an issue.

How Can I Manage My Baby Crying In Their Sleep?

How Can I Manage My Baby Crying In Their Sleep?

With that out of the way you might be thinking, what can you do if your baby cries in their sleep? Well simply put, there could be multiple reasons why your baby’s crying in their sleep, and addressing each one of them might put an end to those crying episodes.

Tips To Soothe A Crying Baby

We all know how exhausting it can be to soothe a crying baby, especially at night. Here we’ve tried to make things easier for you by enlisting soothing methods to make the journey back to dreamland smooth for your baby.

Wait And Watch – Patience Is Key

Don’t rush! It could just be that your little one is going through a transition between light and deep sleep. Most children fall asleep all by themselves after this brief awakening with or without a crying session.

If you pick your baby up while they’re crying in their sleep, you might eventually wake them up, disturbing their sleep, which would make it difficult for them to get back to sleep.

You can gently stroke their tummy or hold them against your chest only if waiting doesn’t work. The key is to make sure you don’t wake these babies up, as this might disrupt their sleep.

Set A Comfortable Environment

Make sure the environment is comfortable enough for the baby. Scan the room, and check for bright lights or loud sounds. Check the thermostat and try to keep the temperature between 66 to 72 Fahrenheit.

Scrutinize if your baby’s clothes are comfortable for them, and check if there’s a need for a diaper change or if your baby is hungry. Offering a pacifier might help them fall asleep quickly.

Hasten The Bedtime Routine But Be Consistent

Try to condense the bedtime routine you’ve set for your little one if you feel they’re tired. Sometimes it’s just their foggy minds that leave these babies irritated and fussy.

An overtired baby can start crying in their sleep, so try to be quick with your bedtime routine. You can also skip some steps if need be, but make sure the environment is top-notch for your angel to sleep well.

Use A Sleep sack

If your baby is too young to roll over, swaddling might help them feel comfortable in their crib. A snuggly swaddle would make your baby feel as if they are still in your womb, safe and sound. But be aware, swaddling an older baby might be a call for disaster.

If your baby is too old for a swaddle, a warm sleep sack might help them feel safer in their crib. Dress them up in their favorite comfy sleep sack and let it do its magic!

Self Soothing

Jumping into the room when you hear your baby crying isn’t the best idea, let them learn self-soothing. To help them fall asleep by themselves make sure the awakenings are quiet and calming.

If your baby cries for more than a minute or two and doesn’t start sleeping on their own, there might be another reason for this episode. Make sure the baby is well-fed and have a clean diaper on.

Address What’s Bothering Them

Other factors might be causing havoc, so try to be cautious of them. Check if your baby is hungry, scared or needs reassurance. Offer a dream feed if you feel they’re hungry or change their diaper if there’s a need. Check if the temperature of the room is optimal and if the crib is comfortable.

What Is The Best Sleeping Pattern For Babies?

Setting a good sleeping pattern for your baby could be a task, but here are some steps you can follow to set up the best sleep pattern for your little one.

Look Out For The Signs Of Tiredness

Make sure you understand when your baby is sleepy or tired. Get them to sleep as soon as they seem to be rubbing their eyes or yawning. Other signs such as a fussy attitude or drowsiness might also indicate that your toddler is ready to sleep.

Most infants by the age of 3-4 months sleep at least for 12-16 hours daily. While by the age of 1, most children sleep for 10 hours each at night and might get 3 naps throughout the day.

Set A Sleep-Wake Cycle

Babies are too young to know when is time to play, so they think the fun never stops! Make sure they have all the fun in the morning, and keep things stimulating for them.

But at night, make sure they understand that it’s time to sleep. Dim the lights and put those toys aside. This way you might be able to help establish positive sleep associations and set their sleeping patterns straight.

Do Not Wake Them Up

If you find your baby up at night crying their heart out while sleeping, don’t wake them by picking them up. Soothe them by stroking their tummy or singing a lullaby.

Should I Be Worried About My Baby Crying In Their Sleep?

Whether it’s your baby’s tummy asking for food or they’re having night terrors, you might be wondering if crying in sleep is a red flag or not.

There are a few different reasons why babies cry in their sleep. It could be due to sleep regression as your baby transitions from one sleep cycle to another. Your baby might be overtired, uncomfortable or teething.

When Should I Take My Baby To The Doctor?

If your baby cries at night and you’re suspecting an illness, it’s better to consult a doctor to see what’s happening. If you’re having trouble figuring out whether it is nighttime terrors or separation anxiety, a pediatrician might help you sort that issue.

After you’ve addressed all the issues that might prompt these late-night crying sessions, and your baby still cries while sleeping, they might be going through something else, and seeking out professional help is the best you can do.

Final Thoughts

As a new parent, you might be wondering, why babies cry in their sleep, and whether you should be worried or not. You might find your baby crying while sleeping due to a bunch of reasons, such as teething, sleep cycle transition, or separation anxiety.

Though the way older babies sleep might be a bit similar to ours, infants transition between sleep cycles way too quickly, ending up spending more of their time in the state of active sleep.

Teething babies might seem crankier or irritable. As your baby’s teeth erupt, they might experience pain that could keep them up all night and leave you with a crying baby.

Other than this, there’s a myriad of factors that might leave your child uncomfortable and fussy, crying in their sleep. A dirty diaper, or tummy gas thanks to indigestion might end up disturbing your baby the whole night!

Even though your instinct might suggest the opposite, try to wait and watch your baby when they start crying, and let them self soothe themselves to sleep.

You can keep an eye on your baby to see if there’s a decrease in appetite or if your baby is not gaining weight, it might be that there’s an underlying issue that needs urgent medical attention.