About one-third of 6-month-olds still don’t sleep through the night, so if yours is one of them, you’re in good company. “Sleeping through the night” at this age means a stretch of six to eight hours, not the eight-plus hours adults expect for themselves. Several biological and developmental factors explain why your baby keeps waking, and most of them are completely normal.
How Infant Sleep Cycles Cause Waking
Babies cycle through sleep differently than adults. They move from drowsiness into light sleep, then deep sleep, then back up through light sleep into a REM (dreaming) phase. Each time they pass from deep sleep back into light sleep, they experience a brief, partial awakening. Adults do this too, but we’ve learned to roll over and fall right back asleep without remembering it. Babies often haven’t developed that skill yet.
When your baby surfaces into light sleep and notices something has changed (you’re no longer holding them, the room is quiet, the rocking has stopped), they fully wake up and cry for help getting back to sleep. This is what sleep consultants call a “sleep association.” If your baby fell asleep nursing, being rocked, or with a pacifier, they may need that same condition recreated every time they hit a light-sleep phase. The fix is gradual: helping your baby practice falling asleep in their crib while drowsy but still awake, so they can reconnect sleep cycles on their own.
Developmental Milestones Disrupt Routines
At six months, your baby’s brain and body are changing fast. They’re learning to roll over, sit without support, babble, and track objects across a room. Their awareness of the environment is increasing sharply. All of this new stimulation can make them more sensitive to sounds, light, and activity, which spills over into nighttime restlessness.
Think of it this way: your baby’s brain is essentially processing a flood of new information, and that processing doesn’t stop at bedtime. Some babies will even “practice” new motor skills in the crib, rolling onto their stomach and then getting stuck or frustrated. This phase is temporary. Once a new skill is mastered and no longer novel, sleep typically settles back down within a few weeks.
Separation Anxiety Is Starting
Around this age, babies begin developing object permanence, the understanding that things (and people) still exist even when out of sight. Before this, when you left the room, you essentially ceased to exist in your baby’s mind. Now your baby knows you’re somewhere, just not here, and that can be distressing. At bedtime, they may resist being put down. In the middle of the night, they may wake and search for you.
Separation anxiety typically peaks between 10 and 18 months and fades during the second half of the second year. At six months, you may be seeing the earliest signs. Short, predictable goodbye routines and consistent responses when your baby wakes can help them feel secure enough to settle.
Hunger, Growth Spurts, and Night Feeds
Six months is a common time for a growth spurt, which tends to last up to about three days and shows up as increased fussiness and hunger. During a spurt, your baby may genuinely need extra calories and wake more often to feed. This is short-lived.
Outside of growth spurts, though, most 6-month-olds don’t need nighttime calories to grow properly. Many babies wake to eat at night simply because they’re used to eating at night. If your baby is gaining weight normally and eating well during the day, those 2 a.m. feeds may be more habit than necessity. Gradually reducing the volume or duration of night feeds over time can help your baby shift those calories to daytime hours.
Teething May Not Be the Culprit
Parents often blame night waking on teething, and it’s an understandable guess since many babies cut their first teeth around six months. But a study published in The Journal of Pediatrics using video monitoring found no significant differences in sleep duration, number of awakenings, or parental visits to the crib between teething nights and non-teething nights. More than half of parents in the study reported sleep disturbances during teething, but the objective video data didn’t back that up.
This doesn’t mean teething is painless. It means that when your baby is waking repeatedly at night, teething is probably not the main driver, and it’s worth looking at other explanations like sleep associations or developmental changes.
The Sleep Environment Matters
A few practical conditions can make a real difference. Your baby should sleep on a firm, flat mattress with only a fitted sheet. No loose blankets, pillows, stuffed animals, or bumpers. Babies sleep best in their own space (a crib, bassinet, or portable play yard) on their backs. Couches, armchairs, swings, and car seats are not safe sleep surfaces.
Room temperature plays a role too. A room that’s too warm or too cool can cause restless sleep. Most babies do well in a room that feels comfortable to a lightly dressed adult. Darkness matters as well. Even small amounts of light can signal to the brain that it’s time to be awake. A dark room with consistent white noise can help your baby stay in deeper sleep longer.
When Waking Signals Something Medical
Most night waking at six months is developmental and behavioral. But a small number of babies have underlying medical causes worth investigating. Obstructive sleep apnea in infants doesn’t always involve loud snoring. Signs include pauses in breathing, restless sleep, snorting or gasping, choking sounds, mouth breathing, and nighttime sweating. During the day, a baby with sleep apnea may seem unusually sleepy or irritable.
Reflux is another possibility. If your baby arches their back during or after feeds, seems uncomfortable lying flat, or spits up frequently, stomach acid moving into the esophagus may be waking them. If you notice any of these patterns, especially pauses in breathing or gasping, it’s worth bringing them up with your pediatrician.
What Actually Helps
The single most effective change for most families is helping babies learn to fall asleep independently at the start of the night. When a baby can go from drowsy to asleep on their own in the crib, they’re far more likely to reconnect sleep cycles without your help at 1 a.m. and 4 a.m. This doesn’t have to mean letting your baby cry alone. There’s a spectrum of approaches, from very gradual (sitting beside the crib and slowly moving farther away over days) to more direct methods. What they all share is the same goal: your baby practices the skill of falling asleep without being held, fed, or rocked all the way to sleep.
Consistency matters more than which method you choose. A predictable bedtime routine (even a short one, like a diaper change, a book, and a song) signals to your baby’s brain that sleep is coming. Keeping wake windows appropriate for their age, typically around two to three hours between naps at six months, prevents overtiredness, which paradoxically makes it harder to fall and stay asleep.
Give any change at least a week before deciding it isn’t working. Baby sleep rarely improves overnight, but it does improve. The fact that your baby wakes up at six months doesn’t mean something is wrong with them. It means their brain is doing exactly what a six-month-old brain does.