Last Updated on January 16, 2026 by Lila Sjöberg
It’s 3 AM. You’ve fed the baby, changed the baby, rocked the baby, and the baby is still wide awake, staring at you like sleep is a concept they’ve never heard of. Meanwhile, you’re so tired you could cry — and maybe you are crying. What is happening, and why won’t this tiny human just sleep?
Key Takeaways
Babies don’t sleep like adults because their sleep cycles are different, shorter, and still developing. Common sleep disruptors include hunger, discomfort, overtiredness, and developmental leaps. Most sleep issues are phases that pass, but understanding why baby won’t sleep helps you respond effectively rather than desperately.
The Short Answer: Babies wake frequently because of short sleep cycles, hunger, discomfort, or developmental changes. The solution depends on the cause — sometimes it’s a feed, sometimes it’s a quieter environment, and sometimes it’s just waiting out a phase.
Let me walk you through the most common reasons babies fight sleep and what actually helps for each.
Understanding Baby Sleep Cycles
Adult sleep cycles last about ninety minutes. Baby sleep cycles? About forty-five to fifty minutes. Between cycles, everyone briefly wakes — adults usually don’t remember these moments, but babies often fully wake and need help getting back to sleep.
This isn’t a flaw in your baby; it’s developmental. Frequent waking actually protected babies throughout human evolution. It’s biologically normal even though it’s exhausting for parents.
Newborns also haven’t developed circadian rhythms yet. They don’t know day from night because that internal clock takes weeks to develop. Until roughly six to eight weeks, expect round-the-clock sleeping and waking with no real pattern.
Hunger: The Obvious Culprit
Small stomachs empty quickly. Newborns often need to eat every two to three hours, including overnight. A hungry baby will not sleep, no matter what else you try.
If baby is waking frequently and seems hungry each time, they probably are hungry. Growth spurts hit around two weeks, three weeks, six weeks, and three months — during these periods, babies often feed more frequently for a few days before settling again.
Breastfed babies sometimes need to feed more often than formula-fed babies because breast milk digests faster. This isn’t a supply problem; it’s just how breast milk works. If baby is gaining weight and producing enough wet diapers, they’re getting enough even if they’re feeding constantly.
Our feeding essentials guide covers gear that makes those endless feeds more manageable.
Overtiredness: The Counterintuitive Problem
It seems logical that a very tired baby would sleep easily. The opposite is often true. Overtired babies get wired, fussy, and fight sleep harder than well-rested ones.
When babies stay awake too long, their bodies produce cortisol — a stress hormone that makes falling asleep harder. The result is a wired, crying baby who seems exhausted but won’t settle.
Watch for sleepy cues: yawning, eye rubbing, looking away from stimulation, fussiness. A consistent bedtime routine helps baby recognize sleep time is approaching. Put baby down at the first signs rather than waiting until they’re obviously tired. Newborns often can’t handle more than forty-five to ninety minutes of awake time before needing sleep again.
If you’ve missed the window and baby is overtired, dim the lights, reduce stimulation, and use whatever soothing method works — rocking, swaying, white noise, feeding. It might take longer to settle an overtired baby, but they will eventually sleep.
Discomfort You Might Not Notice
Babies can’t tell you what’s wrong, so you have to play detective. Common discomforts that disrupt sleep include wet or dirty diapers, being too hot or too cold, gas or digestive discomfort, scratchy clothing tags, or even hair wrapped around a toe (it happens more than you’d think).
Do a quick physical check when baby won’t settle. Change the diaper even if it doesn’t seem that wet. Adjust layers — babies generally need one more layer than adults, but overheating is a real concern too. Feel their chest or back rather than hands or feet to gauge temperature.
Gas can be particularly disruptive. Try burping more frequently during feeds, bicycle kicks to help move gas through, or gentle tummy massage. Some babies need to be held upright for twenty to thirty minutes after feeds before lying down.
The Environment Factor
Where baby sleeps matters. A room that’s too bright, too loud, too quiet, too hot, or too cold can interfere with sleep. Babies are also sensitive to overstimulation — too much activity, noise, or excitement before bed makes settling harder.
Darkness helps signal sleep time. Use blackout curtains or shades for naps and nighttime. White noise can mask household sounds and create a consistent sleep cue — keep it running all night, not just at the beginning.
Cool is better than warm for sleep. Aim for sixty-eight to seventy-two degrees Fahrenheit (20-22°C). Dress baby appropriately and skip heavy blankets, which aren’t safe for infant sleep anyway.
For more on creating safe, sleep-friendly spaces, see our complete sleep training guide.
Developmental Disruptions
Just when you think you’ve figured out sleep, everything changes. Developmental leaps, wonder weeks, growth spurts — whatever you call them, these periods of rapid brain development often disrupt sleep.
Around four months, babies go through a significant sleep regression as their sleep patterns mature. Previously good sleepers suddenly wake frequently. This isn’t a step backward; it’s actually brain development. But it’s exhausting.
Other common sleep disruptions happen around eight to ten months (separation anxiety), twelve months (learning to walk), and eighteen months (language explosion). Each developmental milestone can temporarily affect sleep.
These phases pass. Maintain your routines, offer extra comfort, and know that regression usually resolves within two to six weeks. If crying seems excessive and happens on a schedule, see our colic survival guide.
When to Ask for Help
Some sleep struggles benefit from professional support. If baby seems in pain when lying flat, arches their back, or spits up excessively, reflux might be the culprit — talk to your pediatrician.
If you’ve tried everything and baby’s sleep doesn’t improve over weeks, a sleep consultant can offer personalized strategies. If you’re so exhausted you’re having trouble functioning safely, reach out for help — to family, friends, or professionals.
Your mental health matters. Severe sleep deprivation affects your ability to care for yourself and your baby. It’s not a failure to ask for support.
Frequently Asked Questions
Should I wake a sleeping baby to feed?
In the early weeks, yes — newborns need frequent feeds for growth and to establish milk supply. Once baby regains birth weight and your pediatrician gives the okay, you can usually let baby wake naturally at night. During the day, don’t let newborns sleep more than three hours without feeding.
Will my baby ever sleep through the night?
Eventually, yes. “Sleeping through” is defined as five to six hours for young babies, not the eight hours adults expect. Most babies can do this somewhere between three and six months with appropriate support, though many continue waking occasionally for much longer — and that’s within normal range too.
Is it okay to let baby sleep on me?
During the day while you’re awake and alert, yes — contact napping is normal and many babies prefer it. At night or when you might fall asleep, baby should be in their own safe sleep space. Never sleep with baby on a couch or armchair.
Does dream feeding help?
Dream feeding — feeding baby while they’re still mostly asleep, usually right before you go to bed — helps some babies sleep a longer initial stretch. It doesn’t work for everyone, but it’s worth trying if frequent night waking is your challenge.
When should I consider sleep training?
Most experts recommend waiting until at least four months before formal sleep training, and some suggest six months. Before that, focus on establishing good sleep habits and surviving. When you’re ready, there are gentle methods that don’t involve leaving baby to cry alone.
This exhausting period won’t last forever, even when it feels endless at 4 AM. Baby sleep does improve. Hold on, rest when you can, and know that every parent has stood in that dark nursery wondering the same things you are.
You’re doing better than you think. 🥰
Lila.
