8 minute readWhat could be causing my baby to cry in their sleep?
When you hear your baby crying during the night, it’s usually because they’ve woken themselves up and they’re telling you they’re hungry, uncomfortable, or generally in need of your attention. However, babies often make sounds during their sleep too, and may whimper or cry without waking up at all. But why does this happen?
Well, there are a few possible reasons for your baby crying in their sleep:
They’re transitioning between sleep cycles
Babies’ sleep cycles are typically much shorter (and lighter) than adults’, and they also include a higher percentage of “active” sleep — which we refer to as REM sleep in adults. During this sleep stage, it’s not unusual for them to appear restless, and they’ll often wriggle, twitch, jerk, or even pull faces.
It’s also normal for them to make sounds during active sleep, which can include gurgling, cooing, whimpering and — you guessed it — crying. These cries will usually be mild and short-lived, and will typically subside when they move from the active to the quiet sleep stage, where they settle into a deeper slumber.
They’re uncomfortable or in pain
If your baby feels uncomfortable or is experiencing any kind of pain during the night, this can manifest as crying — sometimes even when they’re still asleep. Discomfort might be caused by factors such as a wet diaper, tight clothing, an awkward sleeping position, or because the temperature in their room is too hot or too cold.
Pain from teething can also cause babies to cry in their sleep, though it can also lead to temporary sleep disturbances where they struggle to settle or wake frequently. Another cause of “sleep crying” might be gas or reflux, which can lead to mild pain or discomfort.
They’re hungry
Of course, when a baby is hungry during the night, they’ll normally wake up and let you know they’re due a feed by crying out. Sometimes, however, as hunger strikes and their bodies are trying to communicate that they need food, they may even begin whimpering or crying before they wake up.
You can feed a baby while they’re still asleep — a practice known as “dream feeding”. While not all babies will respond well to this method (and it’s important to keep them in an upright position to avoid the risk of choking), by gently offering a bottle or a breast before they wake naturally, they may sleep for longer stretches without crying or waking.
They’re experiencing an involuntary reflex
Newborn babies exhibit something called the Moro reflex (also called the “startle reflex”), an involuntary movement where they suddenly throw up their arms and legs or jerk their head backwards, usually in response to sudden movements or loud noises.
Particularly when they’re in a lighter, more active sleep state and more responsive to external stimuli, your baby might experience the Moro reflex while sleeping, which may cause them to let out an involuntary cry as well as twitching or jerking.
They’re having a bad dream
While science hasn’t yet got to the bottom of whether babies dream — and if they do, when they start dreaming and what they dream about — there are some suggestions that children as young as 18 months may experience night terrors.
However, this is thought to be very uncommon (night terrors usually occur in children aged 4 or older), so while it may explain why your toddler is crying in their sleep, it’s more likely to be caused by something other than a scary dream.
They’re just being a baby
Sometimes, babies cry in their sleep simply because, well, it’s a natural part of being a baby. They go through some pretty huge physical, emotional, and neurological changes — which anyone would find overwhelming — and crying is their main way of releasing pent-up energy, processing emotions, or signaling for comfort, even during sleep.
Because their sleep patterns are not fully established and they’ll spend a lot of time in light, active sleep, whimpering and crying can happen as part of their normal sleep cycle. Besides, they don’t always need a specific reason for a cry — sometimes they’re just “working through” the natural rhythms of their growth and development.
Is it normal for babies to cry while they’re sleeping?
It’s certainly not unusual for babies to cry while they’re asleep, particularly when they’re newborn. Since they typically spend about half of their snoozing time in an active sleep state, it’s common for them to appear restless while sleeping — twitching, wriggling, squirming, breathing erratically, and yes, crying.
When should I be concerned about my baby crying during sleep?
There’s usually no reason to be unduly concerned if your baby occasionally cries in their sleep, as it’s often explained away by something quite harmless. However, there may be situations where your baby is crying because they’re uncomfortable, in pain, or feeling unwell, so you should keep an eye out for signs of this.
In these scenarios, for example, sleep crying might indicate something a little more serious:
They’re crying for long periods. If your baby cries occasionally during sleep but usually settles quickly, there’s probably little reason to worry. But if their cries are more persistent, this might indicate they’re uncomfortable or in pain.
They have symptoms of illness. If your baby is crying in their sleep but also has a high temperature, a rash, diarrhea, or anything else that might indicate they’re poorly, it’s best to contact your doctor.
Their sleep patterns suddenly change. If you notice a dramatic change in your baby’s sleep behavior — perhaps they’re more resistant to sleep or more frequently waking — this may suggest an underlying issue.
They’re arching their back. Babies arch their back for many reasons, but if they do so while crying in their sleep, it might be because they have gas, reflux, or an upset stomach and it’s making them feel uncomfortable.
Should I wake my baby if they are crying during sleep?
When your baby cries without fully waking up, it’s usually best to simply wait and observe for a little while. If they let out a few little cries but soon settle down, it’s likely because they’re in a more active sleep state, where it’s normal for them to be restless and occasionally quite vocal.
Intervening too quickly might disturb their natural sleep cycle and make it harder for them to settle back down, so don’t feel the need to rush over and comfort them straight away.
However, if their cries escalate or are accompanied by signs of discomfort — perhaps they have a wet diaper or seem a little hot and bothered — you should try to resolve whatever appears to be troubling them, ideally while trying not to fully wake them.
If your baby continues crying intensely, seems distressed, or you suspect they might be in pain, gently waking them to check for potential issues (hunger or illness, for example) may be the best approach.
How can I soothe my baby if they’re crying in their sleep?
Firstly, it’s important to remember that a baby crying in their sleep is usually no cause for concern, and provided there’s no sign of an underlying issue such as illness or discomfort, they’ll often settle back down on their own without waking or requiring your intervention.
However, if their cries are more intense or persistent, check for signs of discomfort. Do they have a wet diaper? Are their hands cold? Are they a little sweaty? Have they wriggled into an awkward sleeping position? In any of these cases, try to gently resolve the issue without waking them if you can.
Next, look for symptoms of illness. Do they have an unusually high temperature? Are there any changes to their skin — is it mottled or paler than normal? Do they have a rash? Are they frequently coughing? If they display any signs of illness alongside their crying and they’re difficult to soothe, it’s best to check their symptoms with a pediatrician.
If they don’t appear poorly or uncomfortable but they’re still persistently crying in their sleep, you can use gentle touches to reassure them you’re there without waking them — by lightly placing your hand on their chest or back, for example. You can also make soft sounds — through soothing music, white noise, or simply your own voice — to create a more calming environment.
Of course, there’s a stark difference between a light whimper and an emphatic wail, but you know your baby better than anyone — and you’ll usually be able to tell when they’re letting out the occasional weep during a slightly restless sleep stage and when they’re properly crying because they’re uncomfortable or in pain. If you’re unsure, you should never be afraid to pick them up for a cuddle.
It’s perfectly natural for babies to make sounds in their sleep — check out our guide to baby sleep sounds and what they mean — and crying is often one of them. It’s usually nothing to worry about, but if their sleep-contained snivels become more intense or persistent, it’s best to check there’s nothing making them feel uncomfortable or in pain.