Why wont my baby sleep - common causes and tips

In this guide, we explore the reasons why your baby might resist falling asleep, despite your best efforts. Since the causes can vary depending on your baby’s age, we’ve divided the article into two sections: one for newborns and one for babies aged 5-24 months. This way, you can find tailored advice for your baby's specific stage of development.

Reasons why a newborn doesn’t want to sleep:

Here are some common reasons why a newborn baby (0–4 months) may have difficulty falling asleep:

Immature circadian rhythm: If your newborn doesn’t want to go to bed at bedtime or has long waking periods late in the evening or at night, it could be due to their internal clock for night and day not being fully developed yet. This can sometimes result in what is known as day/night confusion, where your baby sleeps their longest period during the day and is most awake at night.

To get support in helping your baby develop a healthy circadian rhythm, you can take our “Sleep course for newborns” in Napper. This course offers valuable insights and strategies to guide you through this phase.

Overtiredness: A newborn’s wake window, or the amount of time they can stay awake before needing to sleep again, is often very short—typically around 30-50 minutes. The window between when you start noticing tiredness cues and when the baby becomes overtired can be very small, making it easy for a newborn to become overtired.

When a baby is overtired, they may feel stressed, upset, and be much harder to put to sleep. With Napper, you can easily track your baby’s wake windows and make sure to put them down for a nap in good time to avoid overtiredness, helping your baby stay calm and well-rested.

Evening fussiness and overstimulation: Newborns are highly sensitive to stimuli and are still adjusting to life outside the womb. It doesn’t take much for them to feel overstimulated. When this happens, they can become upset and have difficulty winding down and falling asleep. To help your baby relax, try retreating to a quiet room with dim lighting, breastfeeding or bottle-feeding, offering a pacifier, and using white noise.

In Napper, you can find 35+ soothing white noise and sleep sounds to help calm your baby. Additionally, feel free to check out our guide on evening fussiness for more tips.

Physical discomfort: Sometimes physical discomfort can disrupt your baby’s ability to fall asleep. Newborns often experience discomfort from gas, as their digestive systems are still adjusting to life outside the womb. If you’re not already doing so, it may help to be diligent about helping your baby burp after each breastfeeding or bottle-feeding.

Babies can also be troubled by issues like reflux, which can cause a burning sensation in their throat. Additionally, your baby might be uncomfortable if they’re too hot or cold, or if they’re lying in a position that doesn’t feel right.

Addressing these potential discomforts can help your baby settle down and sleep more peacefully.

Illness: Sometimes when a baby is sick, they may become restless, upset, and have difficulty calming down and falling asleep.

If your baby is crying inconsolably in a way that seems unusual or if their general condition is affected—such as becoming lethargic, eating less than usual, or breathing rapidly—it's important to contact healthcare providers for advice and support.

Reasons why a baby doesn’t want to sleep (5–24 months)

Here are some common reasons why a baby between 5–24 months may have difficulty falling asleep:

Your baby needs more help to relax: The first step to sleep is always relaxation. When your baby is excited by new experiences or feels that playing and exploring is more fun, they may need extra support to wind down and get drowsy. Try retreating to a quiet room and using multiple calming methods simultaneously. You might combine listening to white noise, rocking your baby, and offering the breast, bottle, or pacifier. These techniques can help your baby relax and prepare for a restful sleep.

You can find 35+ soothing sleep sounds and different types of white noise in Napper.

Your baby isn’t tired enough: If your baby isn’t awake long enough between naps, or if their naps are too frequent or too long, it can make falling asleep more challenging and disrupt nighttime sleep. With Napper, you can easily track your baby’s sleep and get a customized schedule that outlines your baby’s optimal sleep times. This can help ensure your baby is tired enough at bedtime, leading to smoother and more restful nights.

Overtiredness: If your baby stays awake longer than they can handle, they risk becoming overtired. An overtired baby can become stressed, overstimulated, and struggle to calm down and fall asleep. It's important to keep an eye on their wake windows and ensure they get the rest they need before overtiredness sets in, making it easier for them to settle down and sleep peacefully.

Sleep regression: During periods of rapid growth and development, your baby's sleep can be disrupted, leading to more frequent night wakings and difficulties at bedtime. A common example of this is the 4-month sleep regression, where your baby’s sleep pattern shifts from that of a newborn to having sleep cycles more like an adult's.

To learn more, read our guide on sleep regressions at different ages. Understanding why your baby is struggling with sleep can help you find strategies to improve sleep for both of you and create a smoother daily routine.

Remember—during these times, babies often need extra support to fall asleep, and it's always okay to provide that support and be there for your baby. Don’t hesitate to seek help and advice from your healthcare provider if needed.