Quick Answer
Crying or making sounds during sleep is very common in babies and is usually not a sign of distress. A large proportion of infant sleep is spent in active sleep, during which babies can whimper, grunt, cry briefly, move their limbs, and make facial expressions without being fully awake. Pausing before responding often allows baby to settle back down on their own.
Why It Happens
Babies cry in their sleep because a significant portion of infant sleep time is spent in active, or REM, sleep, during which the brain is highly active and sounds and movements are frequent.
In the newborn period, up to half of total sleep time may be spent in active sleep, which is considerably more than in adults. During active sleep you may hear whimpering, brief crying, grunting, and see facial expressions, limb movements, and fluttering eyelids. This is developmentally normal and tends to be mistaken for waking more often than it is. Responding immediately to every sound can fully rouse a baby who would otherwise have stayed asleep and cycled back into deeper sleep.
- Active sleep is easy to mistake for wakefulness. A baby who is squirming, grimacing, and making sounds may be in active sleep rather than actually awake or in distress.
- The proportion of active sleep gradually decreases as babies develop. By 3 to 4 months, most babies spend less time in active sleep and more time in deeper consolidated sleep, which tends to mean fewer sleep sounds overall.
- A cry that lasts more than a minute or two and escalates is more likely to be a genuine wake with a real need. A brief cry that fades, or fluctuating sounds that come and go, is more consistent with active sleep.
- Parents often pick up babies during active sleep who would have self-settled within a minute or two. Waiting briefly before responding tends to be one of the more useful adjustments in the early weeks.
What Parents Can Try
- Pause before going in. A common and understandable reflex is to respond immediately to any sound from baby. Waiting 60 to 90 seconds before entering tends to reveal whether the baby is in active sleep or genuinely waking.
- Observe rather than intervene first. Watching a baby's breathing and movement from the doorway tends to give more useful information than picking them up immediately.
- Watch for signs of full waking: sustained escalating crying, eyes open, reaching or rooting. These are the cues that a need is present rather than a transition through active sleep.
- Accept that some nights will involve more sleep sounds than others. Active sleep tends to be more prominent when babies are going through developmental changes or are overtired.
When To Talk To Your Pediatrician
Occasional crying or sounds in sleep are normal and not a cause for concern. It may be worth mentioning if sleep crying is very frequent and intense across most of the night, if it is accompanied by breath-holding, colour changes, or jerky repetitive movements, or if you are concerned that baby is not getting enough sleep as a result of frequent disturbances.
Key Takeaway
It can be genuinely difficult to watch a baby make distressed-sounding noises and resist the urge to pick them up immediately. Active sleep sounds are so common in young babies, and so frequently mistaken for waking, that simply waiting a moment before responding can be one of the most useful adjustments parents make. Most sleep cries resolve within a minute when left, and responding to them consistently tends to create more full waking rather than less.
Parents Also Ask
- Why Do Newborns Make Noises While Sleeping?
- Is It Normal for Babies to Cry at Night?
- Is It Normal for Babies to Sleep With Their Mouth Open?
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your pediatrician or a qualified healthcare provider with questions about your baby's health.
