Sleep regression - ages, causes and tips

What are sleep regressions?

Sleep regressions refer to periods when a child’s usual sleep pattern is disrupted, making it harder for them to fall asleep or stay asleep through the night. It’s common for children to go through several sleep regressions during their first years, and these phases can be challenging for both the child and the parents.

How do sleep regressions manifest?

Sleep regressions can show up in different ways depending on your child’s age and personality. Common signs include trouble falling asleep, more frequent night wakings, increased crying or discomfort during the night, and shorter naps.

Signs of a sleep regression in your baby may include:

• Waking up more often during the night

• Resisting sleep, such as becoming upset or refusing to go to bed

• Going from having longer naps to only taking short naps

• Doesn’t want to nap at all, even when they’re clearly tired

• Suddenly starting to wake up very early in the morning

• Becoming fussy around bedtime or nap time and only wants to sleep on or near you

• Their sleep pattern or behavior around sleep worsens and lasts longer than just a few days

To figure out if it’s a sleep regression, it’s important to rule out illness or teething, which can also affect sleep in similar ways.

Note: If something seems unusual—like your baby crying intensely, not acting like themselves, or showing signs of pain—it’s important to talk to your healthcare provider or reach out to medical professionals.

Sleep regression vs teething

It can sometimes be tricky to tell the difference between teething and a sleep regression. Typically, teething doesn’t cause much discomfort, but your child might experience itching in their mouth, drool more, and have gums that are irritated, red, and slightly swollen. This can affect both their mood and sleep for a few days.

Teething usually disrupts sleep for a shorter time—often just 1-3 days before the tooth becomes visible—while a sleep regression can last several weeks rather than just a few days.

You’ll know it’s teething once you see that small part of the tooth breaking through the gum. Before that, you might notice other signs of teething, such as:

• Swelling in the gums

• Increased drooling (e.g., you might have to change wet bibs frequently)

• A greater desire to bite on things, like fingers and toys

• Reduced interest in solid food (due to mouth soreness), preferring to nurse/bottle-feed

At what ages are sleep regressions common?

Every child develops at their own pace, so sleep patterns can change at different rates too. However, there are certain ages when sleep regressions tend to be more common. Two key times when sleep regressions often happen are around 4 months and 8 months. That said, individual differences exist, and some babies might show signs of sleep regression a little earlier or later (like experiencing the 4-month sleep regression around 3 or 5 months). Below, we’ve listed the most common ages for sleep regressions.

Around 4 months: At this age, your baby goes through a major developmental phase, both physically and mentally. One of the biggest changes that can impact sleep (and contributes to the well-known four-month sleep regression) is the shift from a newborn sleep pattern to more adult-like sleep stages and cycles. Your baby now moves through different stages of sleep depth, which can lead to more frequent night wakings.

During this time, your baby also becomes more aware of their surroundings, which can lead to feelings of separation anxiety in situations that didn’t bother them before. Your baby may also become more sensitive to differences in their environment between falling asleep and waking up, like being rocked in your arms versus lying alone in a baby nest.

On top of that, your baby is busy practicing new skills during the day, like hand-eye coordination and trying to roll over. All this new activity can lead to overstimulation, which can make sleep quality worse and contribute to more challenging bedtimes—whether it's for naps or nighttime sleep.

Around 8-10 months: At around 8 months, your baby enters another intense phase of development. There's a lot happening with motor skills around this time—many babies start crawling or even standing on their own, and these milestones can affect their sleep habits. On top of that, many children start teething at this age, which can cause mild discomfort that disrupts sleep.

From around 7 months, your baby’s sleep pattern often changes so that they need to be awake longer to feel tired enough to sleep. Because of this, your baby might start resisting that last nap of the day or even skip it altogether, leading to overtiredness by bedtime.

Around 16-19 months: At this age, your child is likely going through a series of major developmental milestones, like learning to walk, expanding their vocabulary, and improving social interactions. As with any big milestone, their sleep might be disrupted for a while, as they can easily become overstimulated.

During this time, they also starts to develop a better understanding of cause and effect and begins to explore how their actions impact their surroundings. This can lead to more challenging bedtimes—whether for naps or at night—as your little one experiments with asserting their will.

Many parents also notice that their child goes through a phase of separation anxiety around this age. This might look like them not wanting to go to bed at all, despite being tired, or trying to get you to stay in the room, even if they previously slept fine in a crib without you nearby.

Around this time, their sleep pattern often shifts, and they may be ready to transition from two naps to one. If this transition hasn’t happened yet, it might lead to your child not being tired at bedtime (or resisting sleep altogether) or struggling with the second nap. If the transition has already occurred, they may need some time to adjust. You might also need to tweak bedtime to avoid them becoming overtired.

2-3 years: At this age children go through periods of intense development that can disrupt sleep. Motor skills take big leaps as they start running, jumping, climbing, kicking, and throwing things. During this time, children are also becoming more independent and socially curious, often testing boundaries and saying "no" more frequently, which can lead to power struggles around bedtime. Nightmares or being afraid of the dark can also become more common, causing more disruptive sleep.

t's also common for children to stop napping during the day around this age. This transition can sometimes lead to overtiredness while your child adjusts or before you’ve had a chance to tweak bedtime. Naps might become inconsistent too—they might nap at daycare out of habit but skip naps at home on weekends, making routines a bit unclear and harder to follow.

How long do sleep regressions last?

Sleep regressions typically last between 2-6 weeks, but sometimes the effects on sleep can linger as new routines and habits are established. That’s why it’s helpful to be mindful of the adjustments you make and to consciously create new routines both during and after these changes in your child’s sleep.

What can be done to improve sleep during a regression?

Sleep regressions often last around 2-6 weeks, but the effects on sleep can sometimes persist longer, depending on how sleep habits are affected. For example, during the 4-month regression, if parents start nursing or bottle-feeding more frequently at night when your baby wakes up, this can shift your baby’s calorie intake more toward nighttime, leading to frequent night wakings that stick around longer. Similarly, adjustments made during the 8-month, 18-month, and 2-3-year-old sleep regressions can cause the effects to last beyond just a few weeks.

To avoid getting stuck in a negative cycle, it’s helpful to read up on and understand the underlying causes of the sleep regression for your child’s specific age.

Read more here:

• 4-month sleep regression: around 3-5 months

• 8-month sleep regression: around 7-9 months

You can also use Napper to help adjust your sleep schedule, see statistics and patterns, and get tips and advice for navigating sleep regressions.