| |

Why Your Baby Won’t Sleep: 10 Surprising Reasons

When your baby won’t sleep, no one in the house is happy. You’re exhausted, your baby is exhausted, your partner and other children are exhausted too.

Most people expect sketchy nighttime sleep during the newborn phase. But what about 4-6 months later and you’re still getting 2 hours of sleep?

7 Surprising Things That Can Ruin Your Baby's Sleep - Why Your Baby Won't Sleep

Sleep isn’t a privilege, it’s a basic human necessity. You and your baby need it to thrive during this phase of life. So, if you’re feeling a little guilty for even looking for baby sleep training advice, don’t. More sleep is possible and you both deserve it.

I’ve gone through humps of time where my daughter’s nighttime sleep was quite shaky. I discovered that while I was working hard to train my daughter to sleep, I was also actively ruining her sleep by ignoring hidden hindrances.

These hindrances are so sneaky, you might night even consider them. And, if they are preventing your baby from sleeping through the night, they’re super easy to correct.

So, let’s dig in and figure out what’s keeping your baby up at night!

From Sleepless to Slumber Baby Sleep Series

If you’re just tuning in, this is the third post in my new baby sleep series. Baby sleep is one of the most important (and scary) aspects of motherhood. If you’re preparing for your baby or in the mix of exhausted, sleepless nights, then this is for you!

Before we begin, here are the other posts:

Why Your Baby Won’t Sleep: 10 Surprising Things that Ruin a Baby’s Sleep

This post contains affiliate links. If you make a purchase from one of the links I will make a small commission at no charge to you. I only recommend what I trust. Blunders in Babyland does not diagnose or offer any medical advice.

 In my opinion, this post is probably the most important of the Sleepless to Slumber series. Here we dive into what is actively ruining your baby’s sleep.

If you are dumbfounded by why your baby won’t sleep, you’re not alone. Baby sleep problems are extremely prevalent in the U.S. Not surprisingly, these baby sleep problems, turn into child sleep problems. In fact, 25-30% children and adolescents suffer from sleep disorders (You don’t want to know how many adults have sleep disorders…)

Based on my personal experience, I believe that no amount of sleep training or schedules will be successful if you don’t take care of the elements that are actively ruining your baby’s sleep. 

A baby’s sleep environment is extremely important. So, we’re going to take a long, hard look at yours.

[mailerlite_form form_id=14]

1. Genetics

Are you a light or heavy sleeper? My husband could snore snooze through a nuclear holocaust. But I can wake up with the lightest tap on the front door.

Like adults, babies have a predisposition for sleep.

A 2011 study by the Pediatric Journal found that while environmental causes and parental guidance mostly contributed to poor sleep habits, there is a genetic component that shouldn’t be ignored.

What to take from that?

Some babies are predisposed to sleep issues. This absolutely does not mean that your baby is doomed, but it does mean that you shouldn’t beat yourself up because your baby won’t sleep!

2. Lack of Swaddling

Using a swaddle was my secret sauce to nighttime sleep. Having said that, she broke out of every swaddle we put her in…except for the Woombie and Miracle Blanket (pictured above).

 (If your baby is older than 3-4 months, just skip this).

In the first few months, your baby will develop her motor skills from the top down. At first, her arms are these freaky flailing things that she randomly sees in the corner of her eyes. She has no idea that these things are hers, and they can be extremely distracting. 

This could definitely be the real reason why your baby won’t sleep. My best advice is to swaddle her up and see what happens. 

I know what you’re thinking: “But my baby doesn’t like to be swaddled!”

I get it, but if you have a wild, crazy baby, there’s a huge chance that your baby needs to be swaddled– even if she hates it at first! My daughter was like that. She screamed, flailed, and destroyed every carefully swaddled blanket I wrapped around her.

Total Houdini Baby.

So, I had to find a swaddle that could handle her. Once I did, it was heaven (My personal favorite is the Woombie swaddle and the Miracle Blanket).

Still not convinced? That’s okay. I wrote the next post for you! How to Swaddle a Baby (That Absolutely Hates Being Swaddled!)

3. Lack of a Bedtime AND Naptime Routine

If you’ve read my article on how to get your baby to sleep through the night, then you know how I believe that an excellent bedtime routine is foundational to everything. If your baby doesn’t have an adequate bedtime/naptime routine, there’s a good chance that his naps are going to be short and unsatisfactory.

When you’re trying to put your baby to sleep, you just can’t expect him to fall asleep on a dime. When you dim the lights, sing a soothing song, do some rocking , this help your baby wind down. In turn, his body reduces cortisol production, and increases melatonin, the sleep hormone.

How you create a bedtime routine is up to you, but whatever you do, keep it consistent.

Bedtime routines can last between 10-20 minutes, depending on your baby’s personality. An extra wiley baby may require a 20 minute bedtime routine.

My routine was simple: About 10 minutes before light’s out, I went to the nursery, closed the blinds, dimmed the lights, and turned on her lullabies. Then, I put her in a sleep sack and cuddled for about 5 minutes. Sometimes we sang, sometimes I read to her. At the end of the 5 minutes (when she was blinking heavily but not quite asleep) I put her in her crib.

If you’re feeling a little bit overwhelmed at this point, Baby Sleep Answers is an online baby sleep training course that walks you through how to get your baby to sleep every single night and GENTLY encourage independent sleep.

RELATED POST: The Sleep Baby Sleep Online Video Program Review

4. Not Enough Day Time Sleep…Or Too Little.

Baby sleep problems can be so confusing. Too much sleep, and you have baby bouncing off the walls at night. Not enough sleep and you still have a cranky little night owl.

There’s a fine line between too much sleep and not enough sleep during the day. For whatever reason, people believe that the less sleep babies have during the day, the more sleep they will have at night.

If there is one thing you take from this section:sleep begets sleep.

Our bodies produce a delicate balance of cortisol and melatonin. These two hormones are like yin and yang; cortisol stimulates us, keeps us awake and alert, while melatonin helps us wind down and go to sleep. 

Let me put this in terms of coffee since that’s my native dialect.

When you wake up, you take a shot of espresso. That makes you alert and helps you get what you need to get done. Over time, the effects of the espresso diminish, and you begin to crash. You have two options: either get a refill or take a nap. But, let’s say you take another shot and you remember that you’re supposed to go to bed early that night. Now you’re all amped up and sleepless!

Likewise, at the end of your baby’s wake cycle, her cortisol diminishes. She needs a nap to recharge. If she doesn’t, her body gives her another shot of cortisol which prevents her from settling in. When you try to put your baby down for a nap when she’s overtired, it’s literally like trying to fall asleep after you’ve had another shot of espresso.

This affects nighttime sleep as well. When she’s exhausted and strung out from all that cortisol, it’s just about impossible to wind down. (This is also why many experts recommend putting your baby to sleep around 7-8PM).

Too Much Sleep

The flip side is letting your baby sleep too much. Many times, babies begin life with their days and nights mixed up…thus the increased nocturnal activity. A great way to combat this is to ensure that your baby never sleeps for more than two hours at a time during the day (obviously this is an estimate).

Yes, this means that sometimes you will actually have to wake your baby up! This is critical though, especially during the newborn days.

The big takeaway here is this:

1. Get your baby to fall asleep at just the right time–right when she shows signs that this sleep window is open

2. Ensure that your baby doesn’t sleep the day away.

(If you’re confused about how much sleep is appropriate for your baby’s age, you can check out this article). 


Baby Won't Sleep - Sleep Props - Baby Sleep Training

5. Physiological Hindrances


I don’t know if I’m not empathetic or observant enough, but it’s always difficult for me to tell what physical ailments are preventing little girl’s sleep.

 The absolute worst is teething. I mean, when aren’t babies teething? You’ve probably seen the symptoms: drooling, pulling at the ears, gnawing on everything, fussiness, light fever, etc.

Teething is a super tricky issue, since it is a legitimate reason why your baby won’t sleep, but there’s not a ton you can do about it. Do what you’ve got to do, but be careful about forming poor sleep habits (like sleep props).  It’s easy for parents to use a sleep prop once in desperation and create a habit out of convenience later.


These two tend to go hand-in-hand.

If your baby is under 4 months, has wet burps, constantly spits up, projectile vomits, or seems like he’s in pain after feeding, have him checked out for GERD. If your baby’s esophagus is burning up, there’s a good chance that’s why your baby won’t sleep.

Having said that,GERD does not have to equal sleepless nights. Yes, it makes it difficult, but you absolutely can have a great sleeper with a GERD baby.

My daughter suffered from horrible gas and reflux during her first couple months. We continued on with our schedule ( her predictable feeding pattern allowed her body to cope better) and tried different methods to ease her discomfort.

Gripe water really helped with these symptoms.

Wonder Weeks & Growth Spurts

Growth spurts and developmental leaps can disrupt everything.

Over time, you’ll notice that your baby goes through predictable fussy periods. All of a sudden your perfect angel is crabby, can’t sleep worth a crap, and then suddenly simmers down a few days later.

These periods, according to the book Wonder Weeks, are caused by developmental leaps. Basically, your baby’s body, brain, and senses are growing and changing, causing several disruptions. For example, if your baby is learning how to roll over, her favorite time to practice will probably be at night or during naps.

If that wasn’t bad enough, your baby will go through predictable growth spurts about once a month (with major ones at regular intervals as well). Your baby’s bones ache, she’s hungrier, and she’s clingy. Total drag for baby sleep.

Unfortunately, there isn’t a ton you can do. Just be patient, stick to your guns, and ride it out.

6. Sound

Really any noise maker will do. However, with 4.5 Star rating and over 4,000 reviews, the Hatch sound maker is the most popular noise maker/nightlight on Amazon.

Sound is a double-edged sword. Too much sound and your baby will undoubtedly wake up. Not enough sound and your baby will wake up at the sound of a pin dropping. Many moms advocate using a white noise machine to help with this issue.

Also, different sounds have a funny way of stimulating your baby.

My advice: try different things. If you use my Sleep Troubleshooting Checklist (including in my free baby sleep training bundle below), make sure you take note of any sounds nearby when your baby wakes early. I think you’ll begin to notice a pattern.

Grab Yours for Free!

    You can unsubscribe anytime. For more details, review our Privacy Policy.

    7. Crib or Mattress Choice

    When I bought my baby’s infant mattress, I felt a little guilty. It was so hard! But SIDS is nothing to mess around with. Despite how hard I thought the mattress was, it’s never disturbed her sleep.

    In fact,  my daughter slept significantly less in her Pack n Play. Don’t get me wrong, I loved the Pack n Play. It was an excellent and inexpensive choice for a bassinet. But, the mattress was much less supportive, shifted when she moved and was quite noisy.

    Here’s my point: when you’re trying to nail down why your baby won’t sleep, you must leave no stone untouched. Test your baby’s mattress. When you apply pressure, does it shift? If you’re using a bassinet, are the support pieces creating a bump in the mattress?

    This is such a small thing, but like us, babies can get uncomfortable.

    7 Surprising Things that Can Ruin Your Baby's Sleep - Baby Sleep Tips

    8: Sleep Props

    If you’re searching for reasons why your baby won’t sleep at night, you’ve probably already heard that sleep props can be the devil!

    Here are just a few examples of a sleep prop:

    • Pacifier
    • White noise
    • Rocking
    • You
    • Swaddling
    • Nursing/bottle

    Are you noticing a trend here? I actually recommended trying some of these things! An object or activity in itself is not a sleep prop. It becomes a sleep prop when your baby needs it in order to get to sleep.

    Let me sidetrack a minute share my own sleep prop experience. In case you haven’t heard, babies have a physiological need to suckle, especially the first couple months. A pacifier, if used properly, can be an excellent sleep training tool (another cool trick I learned from the Baby Whisperer). So, I let my daughter use a pacifier.

    Unfortunately, the pacifier turned evolved into a sleep prop. I gave it to her at times when she could have slept without it. I unintentionally trained her to need the sleep prop.

    The experience was terrible. I debated with my husband every single day if I should wean her off it. Simply put, sleep props kill your baby’s sleep.

    Here’s how you can tell if an object has become a sleep prop:

    • If your baby can’t go to sleep without something, he has a sleep prop.
    • YOU believe that it’s essential to their sleep, but it’s actually killing it.
    • A sleep prop is more about you than your baby. Think about it. Your baby didn’t ask for the sleep prop. You gave it to him so he would sleep. It was convenient, you didn’t know what else to do. The end result was an addiction. Sleep props, inevitably, are a parenting issue (the Baby Whisperer calls it “accidental parenting”).

    Don’t delay in getting rid of the sleep prop. If the time is right, (your baby isn’t sick, suffering from teething pain, you’re on vacation, baby is sick, etc.), then apply some of the sleep training tips (many are no-cry methods!) in my last post and take care of the issue.

    9. A Bad Sleep Environment


    When your baby’s circadian rhythm is still developing, light can be a catalyst for early wakings.

    In addition to brightness, analyze what kind of light is in the room. Babies don’t need a nightlight. So, unless you need it for yourself, you can nix it. If you do need a nightlight in the room, try to look for a warm/red hue. Research indicates that blue lighting can disrupt sleep. 


    Like adults, the temperature can be a sneaky reason why your baby won’t sleep. The ideal temperature for your baby’s nursery is between 68-72 degrees.

    Keep in mind that this is just a general statement. Like me, my daughter runs a bit cold. If her room edges toward the 71 degree mark, I can almost count on her waking up early.

    (If you’re like me and your baby’s room doesn’t have a thermostat, a baby monitor with a temperature sensor is very helpful!)

    Also, keep in mind your baby’s clothing. Some babies like their feet covered when they sleep. Others hate it. Some like sleep sacks, others prefer their legs to be open. It takes some trial-and-error, but once you solve this sneaky issue, you can eliminate your baby sleep problems.

    10. Breastfeeding

    Sometimes, breastfeeding can be one reason why your baby won’t sleep (This is coming from a breastfeeding mama, so bear with me!).

    You’ve probably heard that breastmilk metabolizes faster than formula. Typically, a formula-fed baby, (ruling out all other factors, like weight, illness, etc.) does not need to be fed as much as a breastfed baby. In the early days, this can translate to longer hours of sleep.

    When you consider other breastfeeding-related factors, such as low milk supply, hindmilk/foremilk imbalances, not being able to measure how much your baby is drinking, and tongue tie, formula-fed babies can have the edge.

     If you’re freaking out, don’t worry. You don’t need to switch to formula or begin supplementing with formula.

    Like genetics and physiological hindrances, breastfeeding does make sleeping through the night more difficult, but it doesn’t prevent it. You may have to make certain adjustments to ensure excellent sleep.

    In fact, my baby sleep continuously 5-6 hours through the night by 8 weeks.

    I go more into this in my upcoming post,  but I believe the key to successfully getting your breastfed baby to sleep through the night is:

    • Full feedings
    • Consistent Feedings
    • Dream Feeding

    RELATED POST: How to Have Amazing Sleep With a Breastfed Baby

    Troubleshoot Until You Find Your Baby’s Reasons

    So…are you feeling overwhelmed? I promise, it does get easier! Soon, your baby’s sketchy sleeping hours will be a thing of the past.

    Keep in mind that a baby’s sleep problems are not clear-cut. You can’t just adjust one thing or tinker with another and have an instantly sleeping baby (okay, some people can.) In fact, sleep is such an important and tricky issue, that in Australia, they actually have sleep clinics to train parents to sleep train their children. 

    So, please, do not feel bad.

    The first step is to identify why your baby won’t sleep. There could be multiple factors at play. Sometimes, you need to become somewhat of a mad scientist. Bunker down and conduct experiments, keep a sleep journal, whatever! Do this for a few days and I’m sure you’ll  find a few nasty patterns.

    If this sounds a little exhausting, I totally get it.

    I created this sleep troubleshooting checklist below to streamline the process. I made this for myself because I didn’t have time to write down every detail. This worksheet was a life-saver.

    Once you narrow down the root of why your baby won’t sleep, using sleep training is much more successful!

    I hope this post helps you, Mama. Don’t beat yourself up if your head is spinning from your baby’s sleep problem. Babies are not for the faint of heart.

    Discovering the heart of the issue takes some work but you will get there. Download the checklist, give it a try, and let me know what happens!

    Until next time!

    NEXT POST: How to Swaddle a Baby (That Absolutely Hates Being Swaddled)

    [mailerlite_form form_id=14]

    Similar Posts

    Leave a Reply

    Your email address will not be published. Required fields are marked *

    I accept the Privacy Policy


    1. Thanks Erin! Your posts are encouraging and realistic! We are working on a new sleep routine with our 4 month old. So far we’ve gone from 40 minute naps to 2 hour ones. Great progress I would say.

      Question: Do you think drinking caffeine (but also waiting at least an hour before feeding) would have a huge impact on a babies sleep habits?

      1. Hey, Hannah! Thanks for your kind words! I agree, that’s AMAZING!
        That’s actually a really good question. Caffeine can pass into your breast milk, but I think the levels need to be pretty high for it to affect your baby’s sleep. It really depends on your baby’s sensitivity too. You can always cut back a cup or two for a week or so and see if you notice any improvement!