Your toddler was finally sleeping through, and now they’re calling for you at 2 a.m., fighting naps and crying the moment you leave the room at bedtime. If you’ve searched 18 month sleep regression, you probably want to know three things: is this normal, why is it happening now, and what can you actually do tonight. Here is an honest answer, a short check to find the likely cause, and the signs that mean it’s time to call your pediatrician.
This page is part of our baby sleep schedule by age guide, which covers sleep from newborn to 2 years.
Quick answer: 18 month sleep regression
- Is it real? “Sleep regression” is a popular term, not a medical diagnosis. But many parents notice sleep gets harder for a while in the second year, and there are clear reasons why.
- Common causes: separation anxiety, big new skills like walking and first words, a nap change, teething, illness or a change in routine.
- How much sleep: the American Academy of Pediatrics (AAP) recommends 11 to 14 hours in 24 hours for children 1 to 2 years old, including naps.
- What helps most: a predictable bedtime routine, the same calm response each night, and a nap schedule that fits your toddler’s age.
- How long: there is no official timeline. The AAP says separation anxiety usually fades somewhere around the second birthday.
- Call your pediatrician if poor sleep comes with fever, pain, snoring or breathing pauses, or if your toddler loses skills they used to have.
Why sleep can change around 18 months
There is no research that defines an “18-month regression”, so we won’t give you a fixed age or length. What is well described is everything that happens in the middle of the second year.
- Separation anxiety. The AAP calls it a normal stage in children’s emotional development. A child may wake several times and cry anxiously for one or both parents, and may need reassurance several times, night after night. Our guide to stranger and separation anxiety explains more.
- Big skills. The CDC milestone checklist for 18 months includes walking without holding on, trying to say three or more words besides “mama” or “dada”, and moving away from you while looking to make sure you are close by. A brain this busy can find it harder to switch off.
- Wanting a say. Toddlers are learning that their choices matter. Bedtime is a natural place to test that.
- Nap changes. Many toddlers move from 2 naps to 1 somewhere between about 15 and 18 months. During the switch, some days are overtired and some days nap too late.
- Teething. Molars often come in during the second year; see teething signs and safe remedies.
- Illness. Fall and winter bring colds and ear infections, which can disturb sleep for days. See caring for a sick baby at night.
The 4-question check
Before you change everything, take a week to notice the pattern. These four questions point you to the most likely cause:
| Question | If the answer is yes | What can help |
|---|---|---|
| 1. Is it mostly bedtime: crying when you leave, asking for “one more”? | Separation anxiety or testing limits | A short, predictable routine, a calm goodbye and the same response every night |
| 2. Is it night waking, and does your child settle quickly when you come in? | Separation anxiety | Brief, boring reassurance in the crib, then leave; keep the lights low |
| 3. Has the nap changed, or is your toddler napping late in the day? | Nap transition | Move to 1 midday nap gradually, with an earlier bedtime while they adjust |
| 4. Is it new, with fever, ear pulling, drooling, a runny nose or a change in appetite? | Illness or teething | Comfort first; call your pediatrician if your child seems unwell (see below) |
Often it’s more than one thing at once. Fix the easiest part first, usually the timing of the nap and bedtime, then work on the routine.
What can help, step by step
- Keep the routine short and the same. The AAP notes that children find separations easier when they are part of a predictable routine. Bath or wash, pajamas, teeth, a book, a song, bed. Our bedtime routine guide has a simple template.
- Say goodnight clearly. The AAP suggests letting children know in a matter-of-fact way when you have to leave them. Sneaking out can make the next separation harder.
- Offer choices before bed, not in bed. “Blue pajamas or stars?” gives your toddler some control without stretching bedtime.
- Respond the same way every time. Whether you check in quickly, sit by the crib or use another approach, consistency matters more than the method. If you’re thinking about a more structured approach, see sleep training methods.
- Watch the nap. A nap that ends late in the afternoon can push bedtime late. A nap that is too short can make the evening hard. Small changes of 15 to 30 minutes are enough.
- Mind the clock change. In the US, clocks go back on November 1, which can bring earlier wake-ups. See our daylight saving time plan and baby wakes up at 5am.
- Look after yourself. Take turns with a partner or helper if you can. A rough few weeks is easier with sleep in shifts.
Sample day for an 18 month old
This is an example to adjust, not a rule. Shift it to match your toddler’s usual wake-up time.
| Time | What happens |
|---|---|
| 6:45 a.m. | Wake up, milk or breakfast |
| 9:30 a.m. | Snack, outdoor play |
| 12:30 p.m. | Lunch, then nap (often about 1.5 to 2.5 hours) |
| 3:30 p.m. | Snack, play |
| 5:30 p.m. | Dinner |
| 6:45 p.m. | Bedtime routine: bath or wash, pajamas, teeth, book, song |
| 7:15 p.m. | Lights out |
Related: a sleep sack for toddlers who climb or wake at night.
When to talk to your doctor
Most sleep changes in the second year pass with time and a steady routine. Call your pediatrician if:
- poor sleep comes with fever, pulling at the ears, pain, vomiting or a rash;
- your toddler snores loudly most nights, breathes noisily or seems to pause in breathing during sleep;
- sleep problems are affecting your child’s mood or behavior during the day, or have lasted more than a few weeks without improving;
- your toddler has lost skills they once had, such as words or walking (the CDC advises acting early);
- you’re worried about your child’s development or you feel unable to cope. Your own doctor can help too.
Call 911 if your child is struggling to breathe, turns blue or gray, or cannot be woken. See also when to call the pediatrician.
Frequently asked questions
Is the 18 month sleep regression real?
It is not a medical diagnosis, and no official source defines it. But sleep often changes around this age because of separation anxiety, new skills and nap transitions, so what you’re seeing is common.
How long does the 18 month sleep regression last?
There is no official length, and it varies from child to child. The AAP says separation anxiety usually fades somewhere around the second birthday. If sleep has not improved after a few weeks, or other symptoms appear, talk to your pediatrician.
What are the signs of the 18 month sleep regression?
Parents often notice new night waking, crying at bedtime, fighting the nap and wanting a parent nearby. If your toddler also has a fever, pain or breathing changes, look for an illness instead.
Should my 18 month old still take a nap?
Yes, most toddlers this age still nap. Many take 1 nap a day by about 18 months, while some still need 2. The AAP total for 1 to 2 years is 11 to 14 hours in 24 hours, including naps.
Is it OK to go in when my toddler cries at night?
Yes. The AAP says your child may need reassurance several times, night after night, while separation anxiety lasts. Brief, calm and consistent visits help your toddler learn that you come back.
What did the 12-month stage look like?
See our 12-month milestones guide for what comes just before this stage.
Browse more sleep guides on our baby sleep page.
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Sources
- HealthyChildren.org (AAP): Healthy Sleep Habits: How Many Hours Does Your Child Need?
- HealthyChildren.org (AAP): Separation Anxiety and Sleeping
- CDC: Important Milestones: Your Child By Eighteen Months
This article is for general information only and is not a substitute for medical advice. If you’re worried about your child, call your pediatrician, or 911 in an emergency.