Baby Crying in Sleep: 6 Reasons and How To Soothe Them

When your baby starts crying, your instinct would probably tell you to go and check on them and see what’s wrong. Most of the time, it could be that they’re hungry but what happens if your baby is crying in their sleep? Could it be a nightmare?

Let’s look at 6 reasons why your baby may be crying while asleep and tips to soothe them back to bed.

6 Reasons Why Babies Cry in Their Sleep

1. Transitioning between sleep cycles

All of us, including babies, have a sleep cycle. Unlike adults, babies tend to sleep in short bursts, with each sleep lasting 20-50 minutes long.

Babies also tend to be light sleepers which means that they spend most of their sleeping time in Rapid Eye Movement (REM) sleep or active sleep. This also means they wake up more frequently [1].

While in REM sleep, babies might exhibit the following symptoms:

• breathe shallowly
• twitch their arms or legs
• flutter their eyes while closed
• make noises (e.g. whimper, cry, etc.)

During the transition from one sleep cycle to the next, babies may wake up briefly and cry out for a few minutes as they adjust to a different sleep stage and fall asleep. This is often seen as a normal part of their sleep development.

So, it may be nothing to worry about if you hear your baby cry while sleeping. However, it’s important to rule out other potential causes, which we’ll explore in the following sections.

2. They may be hungry

Another possible reason why your baby may cry is due to hunger. Babies may have tiny tummies but they are constantly growing. This means that they would get hungry often, especially throughout the night [2].

Over the first few weeks and months, babies need to be fed every 2 to 4 hours [3]. Whenever babies get hungry, they show a few early signs like putting their hands in their mouth, clenching hands, or puckering their lips [4].

If it’s late at night, you may not be able to look out for these cues. Hence, the only way for your baby to let you know it’s hungry is to cry. Crying is often a late sign of hunger.

3. Overtiredness

Young babies can easily become overtired, especially in environments with a lot of noise, light, or activity. When this happens, it triggers the production of cortisol and adrenaline in their bodies.

With elevated hormone levels, falling asleep or staying asleep may be harder. This can lead to more frequent waking and crying during sleep [5].

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4. Teething issues

Most babies start to grow their teeth out at around 6 months old. This period may be uncomfortable as their gums become more sensitive.

Sometimes, they may cause no pain or discomfort. In most cases, their gums could swell and feel sore as the unerupted tooth grows [6]. This often leads to nighttime crying as your baby sleeps at night.

It’s your baby’s way of letting you the discomfort that he is feeling. If it happens frequently, you may want to check with a pediatrician for options to relieve the discomfort.

5. Separation anxiety

Separation anxiety is also another potential reason why your baby may cry as he sleeps. Separation anxiety in babies may start as early as 4 months old but for most babies, it happens when they are around 8 months old [7].

During these months, your baby starts to develop something called ‘object permanence’. Object permanence is the awareness of an object or person existing even when you can’t see or hear them. This development contributes to separation anxiety [8].

So if you leave your baby in a separate room at night to sleep, it may trigger them to cry as they are unable to sense your presence. If this happens often, consider sleep training. Sleep training is a technique of leaving your baby to learn to fall asleep on his own.

6. Sleep Regression

Lastly, we have sleep regression. Sleep regression is a phenomenon that happens when you are unable to sleep well anymore.

The biggest sleep regression that a baby may go through is when he is at 4 months old. Your baby wakes up multiple times, fussing and crying in their sleep.

This sleep regression is caused by your baby adapting to their true circadian rhythm with ‘deep’ and ‘light’ sleep cycles as well as developmental changes. As the body tries to transition between the cycles of sleep, it causes them to wake more often and cry to get back to sleep [9].

Based on these reasons, it’s rather normal for babies to cry in their sleep. It may not always be a cause for concern.

4 Tips to Soothe a Crying Baby

In this case, what should you do when your baby starts crying in their sleep?

Here are 4 tips to help you soothe your crying baby and help them fall back asleep.

1. Carry and rock your baby: Try to pick them up gently, place them in your arms, and rock them till they fall asleep. As you rock your baby, stand with your feet slightly apart and move back and forth at the hips. Alternatively, you may bounce lightly by bending your knees repeatedly [10].
2. Play some gentle sleep sounds: You can also try to play some gentle sounds such as a lullaby or white noise to calm your baby down and ease into a deep sleep. Check out ShutEye® for a wide collection of sleep sounds.
3. Swaddle your baby: Swaddle your baby by wrapping them tightly in a tight blanket. The feeling of being wrapped tightly could feel comforting for your baby as it reminds them of being in a womb. You may use a sleep sack for older babies [11].
4. Gently rub your baby’s back: Hold your baby close to you as you rub your baby’s back. This response can help to soothe your baby’s cries as it feels warm and reassuring.

You may also like: 10 Best Sleep Tips for Newborns

When to Worry About Crying in Sleep

It’s normal for babies to cry during sleep but if your baby cries for a long time and can’t be pacified, it may be a sign of a medical issue.

If your baby’s cries are associated with these symptoms:

• Has trouble breathing, throaty noise while breathing
• Has high temperature with cold hands and feet
• Blue or pale skin
• Has a fit or violently vomiting
• Signs of teething pain

Your baby could be unwell or in pain so you should seek medical advice as soon as possible.

Conclusion

It is a normal behavior for babies to cry in their sleep. By recognizing the common reasons (teething, hunger, transitioning from sleep cycles, separation anxiety, sleep regression, or overtiredness), you can take steps to soothe your baby and help them get a good night’s rest.

Check out our patented sleep tracking app, ShutEye® for more sleep tips and sleep aids that are useful for new parents and those contemplating parenthood.

Track your sleep cycle and kickstart your journey to better sleep

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