18 Month Sleep Regression: What Causes It and What to Do?

Amber LoRe - Sleep Consultant / Pediatric sleep consultant / Updated Nov 30, 2021
18 month old sleep regression

If your toddler is around 18 months old and experiencing sudden sleep challenges, you may be dealing with the dreaded “18 Month Sleep Regression.” While this stage in your toddler’s life  has its challenges, it’s also a reminder of a child’s growth and development. If we want better sleep our approach will need to develop too.


Between 14-18 months of age we tend to see recurrent sleep issues arise. Parents of 1 ½ year olds often report a toddler sleep regression that includes increased night wakings as well as nap and bedtime refusal. This “18 Month Sleep Regression” will impact some toddlers, but certainly not all. The degree to which this period of development impacts a child’s sleep will depend on the individual child’s routines and their parent’s response. Let’s take a look at some of the developmental factors that can influence sleep patterns at this age.

Toddler laying asleep on bed cuddling teddy bear

In the 14 -18 month age group, we see children really start settling into toddlerhood. That means they’re beginning to test boundaries and seek independence. Instead of laying down and falling asleep at bedtime like they may have been doing, they’re suddenly exploring ideas like, “Hmmm...what would happen if I just kept playing instead? Or maybe I’ll throw all of my pacifiers on the floor! Hey, I wonder if I can climb out of this crib...” 

Heightened separation anxiety (where separating from a caregiver can cause a child to become very upset) is often at play at this age. Separation anxiety is a healthy part of child development, with some phases being more extreme than others.  So now, not only may your child feel clingier, they’ll often decide to experiment at this age with refusing to peacefully lay down and sleep.

During this period, the first molars often start to break through the gums. Due to their size, molars can be especially painful as they emerge. As a result, children often want more comfort from their parents, particularly at sleep times. 

To complicate matters, it’s also at this age that most children drop a nap and transition to one nap in the middle of the day. As children adjust to staying awake for longer periods, they’re often overtired by bedtime. This, in turn, can lead to a surge in the hormone cortisol, which makes it harder to fall asleep and stay asleep.

Generally, when experts talk about sleep regressions, we’re talking about a situation where the quality and ease of a child’s sleep suddenly declines. Parents may notice a variety of changes in sleep habits. Signs of a regression include a refusal to sleep at bedtime, increased nighttime wakings, early waking, nap refusal, and shorter naps.

Most sleep regressions at this age last 2-6 weeks. Keep in mind however, that not all children go through a sleep regression around 18 months. While the regression typically lasts 2-6 weeks,  sometimes a parent’s response to the new sleep challenges can create new dependencies which turn a temporary phase into a long-term sleep problem.

All of these rapid developmental changes can be a recipe for one cranky toddler. A toddler who likely lacks the communication skills necessary to calmly explain why they don’t want you to leave at bedtime, or why they’re waking you up repeatedly each night. Cue the tears (and not just from your toddler). Luckily, there are ways to alleviate the impact and improve sleep.

When younger toddlers still take two naps their bedtime can start to creep later, which is often welcome. Afterall, later bedtimes can allow for a more leisurely dinner or additional play time together before bed. 

However, once a child drops to one nap, bedtime suddenly needs to be much earlier again (at least in the beginning). Many children in this age group can only comfortably stay awake for about 5 hours at a time. That means if their nap ends at 1:00 PM, they may be ready for bedtime as early as 6:00 PM, at first.

Use our SweetSpot® sleep time predictor to determine the best nap and bedtime for your child after their nap transition. This can help limit overtiredness and the resulting sleep issues it can bring, especially during this adjustment period.

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By 15 months of age many children are in the midst of dropping a nap. This transition period may mean frequently missed naps. When naps are skipped, children can become overtired very easily. This, in turn, can result in difficulty falling asleep and staying asleep. 

While it’s important to follow an age-appropriate schedule to encourage day sleep, stimulating those developing minds and bodies in the morning can also help toddlers nap better, too. Roll a ball. Play simple games - like puzzles and blocks. Limit screen time. Get out in the sunshine when you can. These simple measures can mean a better shot at naptime.

During the transition to one nap, naps are often skipped despite our best efforts. Moving bedtime earlier on those days can help limit overtiredness. 

Once a child starts to explore and test boundaries, it’s the perfect time to start setting limits. Have clear routines around sleep times, if you don’t already. We recommend having a consistent pre-sleep routine that ends in the same definitive way each time. For example, you might end the routine with the same lullaby each night before you kiss your child goodnight.

Setting limits and consistently enforcing your routine will help children understand what to expect at sleep times. This leads to a feeling of security and ultimately less tears. However, the more we “give in” and deviate from the routine, the more likely we are to see sleep disruptions. When we intermittently reinforce boundary-testing behavior (by giving in sometimes, but not others), this only encourages the behavior and sends a confusing message to the child. 

While consistently enforcing healthy sleep routines is vital to maintaining your child’s sleep progress, there are times when kids need some extra TLC. 

If your child is suddenly struggling to fall asleep independently, it makes sense that you’ll want to offer them more comfort, especially if you suspect they’re in pain from teething or going through a strong bout of separation anxiety. Consider lengthening your pre-sleep routines to include extra cuddle time. Speak to your pediatrician about pain medication, if necessary.

Parents who are used to independent sleepers may decide to help their child fall asleep on a temporary basis. While it’s understandable to want to help your toddler get the sleep they need, keep in mind that you’ll be re-setting their expectations surrounding sleep. If you start doing more to help your child fall asleep (like staying in the room when you used to leave), your child will start to expect that every night - and possibly throughout the night as well. 

Studies show that when children learn to fall asleep without parental help at bedtime they have fewer sleep problems. If your child needs your assistance to fall asleep, consider sleep training. Contrary to popular opinion, sleep training isn’t synonymous with “crying it out” (though that is one approach). Instead, it’s a process to help your child strengthen their independent sleeping skills. There are many sleep training options. 

For instance, if you sit next to the crib at night until your child falls asleep, consider the “fading approach.” This is a gradual method to transition away from helping your toddler fall all the way to sleep with your help. Each night, you move a little bit further away from the crib, giving your child a little more space and independence to work on falling asleep with less help. Ideally, you’ll be in the doorway within a week. Once your child gets used to falling asleep with you further away, you can sit outside of the door. Use your voice to console, as needed. Eventually, you’ll get to the point where you can say goodnight at bedtime and your child will fall asleep without you in the room. This should improve sleep.

Parents seeking a quicker solution to their child’s sleep problems may choose a “controlled crying” method. While there are many variations, parents leave their child to cry for intervals until they fall asleep on their own.  Although these methods tend to produce faster results, we want to use caution if a toddler is strong and determined enough to climb out of their crib. In which case, some parents will get “creative” by rotating the crib around so the lower side is against the wall, as an example.

If you’re a parent who has decided to start helping their child fall asleep again during a regression, know that this doesn’t need to be a permanent situation. When your family is ready, we can help you get back on track. Huckleberry Premium was created to make sleep consultations for children more affordable for families. We take into consideration each family's individual lifestyle as well as their sleep goals when working to create a successful sleep plan. If you are interested in more personalized analysis and guidance for your child, sign up for Huckleberry Premium.

18 Month Sleep Regression FAQ

Q: Why does my 18 month old keep waking up at night?


The most common cause of night waking at this age is due to overtiredness and sleep onset associations. Children who skip naps or go to bed too late may be overtired, resulting in more wakings. Furthermore, if a child falls asleep with their parent’s help at bedtime (otherwise known as a “sleep onset association”), this can mean the child will want that same help when they wake during the night.

Q: Can the 18 Month Sleep Regression happen early?


The 18 month sleep regression can happen anytime between 14-18 months old. Don’t be fooled by the name - it could just as easily be called the 15 month or 16 month sleep regression.

Q: Do all babies go through the 18 Month Sleep Regression?


No. Although the “18 month” sleep regression is widely discussed as something all children experience, it’s important to note that this period of rapid development doesn't occur at the exact same age for all children and doesn't always wreck havoc on young sleepers’ routines. The sleep habits of the individual child and the parent’s response both play a large role in whether sleep will regress.