Why Your 18-Month-Old’s Sleep Just Fell Apart, and How to Get It Back on Track

Let’s talk about one of the most notorious (and frankly exhausting) sleep disruptions in toddlerhood: the 18-month sleep regression.

If you’ve found yourself suddenly dealing with early morning wake-ups, skipped naps, intense bedtime battles, or a once-sleeping child who is now up for hours overnight—you're not alone. And no, you didn’t “mess anything up.” This regression is real, and it’s a tough one.

But here’s the good news: like all regressions, it is temporary—and there are ways to navigate it without completely losing your mind (or your sleep).

This blog will break down why the 18-month regression happens, what it looks like, and how to support your toddler (and yourself!) through it.

Why the 18-Month Sleep Regression Happens

There’s a lot going on developmentally around this age—and it all shows up in sleep.

Your toddler is likely:

• Learning 10+ new words a day

• Practicing independence (read: resisting everything)

• Experiencing new fears or separation anxiety

• Testing boundaries and routines

• Possibly transitioning to one nap (or refusing naps altogether)

Sleep often takes a back seat during big brain leaps and emotional growth. Toddlers at this age are becoming increasingly aware of their environment—and they’re realizing that saying “no” gets a reaction. That awareness can spark pushback at bedtime, resistance to naps, or a sudden refusal to sleep in their crib.

Add teething, molars, or a recent illness into the mix and… yep, it’s the perfect storm.

Signs of the 18-Month Regression

Not sure if you’re in the thick of it? Here are some classic signs:

• Sudden nap refusal (even if they were great nappers before)

• Bedtime stalling (asking for water, another hug, or one more story)

• Overnight wake-ups that last 1–3 hours, often with crying or clinginess

• Early morning wakings (hello, 4:45am)

• Increased separation anxiety, especially at bedtime

• Tantrums and big feelings around sleep routines

If your toddler was sleeping well and then all of a sudden isn’t—especially around 17–19 months—this regression could be to blame.

What to Do (and Not Do)

Let’s talk strategy. You don’t have to totally overhaul your sleep routines, but here’s what helps most during this phase:

1. Stay consistent

This is not the time to ditch your routine (even if it feels like it’s not “working” right now). Your toddler needs predictability. Keep offering naps at the same time, follow your normal bedtime steps, and stick with what you were doing before the regression hit.

Even if your toddler skips a nap or takes forever to fall asleep, staying consistent helps them feel secure—and makes it easier to bounce back once the regression passes.

2. Set loving boundaries

Toddlers are pros at pushing limits. They want to know: “What happens if I say no?” “Will mom stay longer if I scream?” “Can I skip bedtime if I keep asking for snacks?”

Respond with warmth, but hold the boundary. “I love you, it’s time for sleep,” goes a long way when said calmly and firmly. Over-explaining or giving too many chances usually backfires during this stage.

3. Offer extra connection before bedtime

Sometimes toddlers resist bedtime because it means separation. Build in 10–15 minutes of focused, one-on-one time before the bedtime routine. Play, read, snuggle—whatever feels calming and connected. This helps fill their “connection cup” so they’re less likely to protest when it’s time to sleep.

4. Don’t rush the nap transition

Some toddlers look like they’re ready to drop to one nap around 18 months—but many aren’t quite there. If naps have suddenly fallen apart, try capping the morning nap at 30–45 minutes to preserve the afternoon nap. Most toddlers don’t truly settle into a one-nap schedule until closer to 18–20 months.

5. Protect your own sleep

If your toddler is up for hours overnight, make sure you're setting limits around how long you stay in the room. Avoid forming new sleep habits you don’t want to keep long-term (like co-sleeping all night or bringing them to your bed unless that’s your family’s norm). It’s okay to reassure them—and it’s also okay to get back to sleep yourself.

When the Regression Becomes Something More

Most regressions resolve within a few weeks. But if sleep has completely unraveled and you’re not seeing any improvement after 3–4 weeks, it might be time to reassess.

Ask yourself:

• Has my toddler developed new sleep associations (like needing to be rocked to sleep)?

• Are we missing a solid daily routine or age-appropriate schedule?

• Has our response to sleep protests become inconsistent or unclear?

• Do we need to re-establish sleep boundaries or reset expectations?

Sometimes the regression uncovers sleep habits that aren’t sustainable long-term—and that’s okay. You can always pause, reset, and come back to sleep training with fresh eyes and a supportive plan.

Final Thoughts

The 18-month sleep regression is tough. It’s frustrating, exhausting, and can feel like a giant step backward. But it’s also a sign that your toddler is growing, learning, and becoming more aware of the world around them.

Hang in there.

Keep your routines, hold your boundaries, and offer lots of love and connection. This phase doesn’t last forever—and with the right support, your little one will get back to more restful nights.

And if sleep still feels hard weeks later? I’ve got you. Whether you need a gentle refresher or a full reset, my toddler sleep packages are here to help. Book your free 15-minute call and let’s get your family the rest you deserve. 💛