Why do babies arch their back?

Scary and exasperating as it is, it's common – and perfectly normal – for babies and toddlers to throw themselves backward and arch their back when upset. This often happens when you're holding them, which can lead to scary moments as you try to keep your child from launching backward out of your arms.

Being a baby or toddler can be tough! With limited communication skills, crying and thrashing about is their best bet at expressing frustration. Whether they're tired, hungry, bored, or in pain, they want your attention because they trust you to help with whatever's giving them grief.

Until your little one is older, they won't have the skills to navigate big emotions in ways that feel comfortable to the people around them. So when they throw themself back, your main goal is to keep them safe and offer comfort until they're calm again.

Why your baby is arching their back

Back arching isn't uncommon and it typically isn't a cause for concern. While there could be a few reasons your baby is arching their back or throwing themself around, in most cases the cause will be something as simple as frustration or an upset stomach.

In very rare cases, back arching can be a symptom of a serious medical condition. If you're concerned about a medical issue in your baby, keep an eye out for other symptoms, since back arching on its own is often nothing serious.

Here are some reasons your baby might be arching their back or throwing themself backward.

Your baby is having big emotions

As your baby grows older, their emotions are changing and becoming more complex.  You've probably noticed how your little one is growing more particular about what they want and don't want, and responding with anger or frustration when things aren't quite what they expected.

In some cases, babies and toddlers will arch their back because they're upset and they have a limited number of ways to communicate their emotions. Sometimes, it might be obvious why they're angry or sad, but sometimes it won't be so clear. Outside of soothing your upset baby and keeping them safe from hurting themself, the best thing you can do is remain calm while you wait for your baby to settle down.

Your baby is frustrated with feedings

Both breastfed and bottle-fed babies might get upset if they're hungry. (Just like adults!) For example, if they're growing impatient waiting for your milk to let down or the bottle flow is slower than they'd like, they might arch their back and fuss.

The opposite is also true – if you have a strong letdown, the flow of the bottle is too strong, or your baby is full, arching their back could be a clue they need a break or a change.

Your baby is throwing a temper tantrum

Older babies and toddlers learn to express their anger in a variety of ways, and back arching could be a part of a tantrum. New and more complicated emotions, paired with a lack of control, can be really difficult for little ones. With very few ways to communicate their frustration and disappointment, they turn to tantrums to get the point across.

If your child is like most, the back-arching sessions signal nothing more than your child's growing independence and signify that their emotional development is right on track. So brace yourself and hang on: This won't be the last time you'll have to remain calm as your child's temper flares out of control.

Your baby is colicky

If your baby is very young and they're arching their back while crying, it may be colic. Around 2 weeks, some babies start crying excessively and don't calm down with the typical tricks. Technically, colic applies to babies younger than 5 months who cry for longer than 3 hours at a time at least three days out of the week. Along with their screams, they might arch their back and thrash around.

For both parents and babies, colic is an exhausting and challenging phase. Colic has confounded experts who have struggled to pinpoint causes for this short-term condition in babies. Some studies say allergies, maternal smoking, overstimulation, and gastroesophageal reflux may be reasons for colic.

If you think your baby is colicky, talk to their pediatrician. They might suggest changes to your baby's diet or routine, or medication to help your little one feel better until they grow out of their colic around 5 or 6 months.

Your baby is gassy or has reflux

Your baby might not have colic, but they might be arching their back because their stomach is upset. This is often true when your notice back-arching exclusively after feeding your baby, along with gas. If your baby also turns their head from side to side, flexes their elbows, extends their hips, and shows signs they're uncomfortable when they spit up, they might have gastroesophageal reflux disease (GERD).

Babies with GERD may not gain weight appropriately, refuse to eat, or act upset after nursing. Untreated reflux or GERD can be detrimental to your little one's well-being, especially if they aren't gaining weight. If you think your baby has GERD, talk with their doctor about changes you can make to improve their symptoms.

Other reasons your baby might be arching their back

In very rare cases, babies who arch their back could do so because of an underlying medical condition. Most of the time, back arching isn't the only symptom a baby will show if they have a medical condition.

Here's a look at what could be going on in the very unlikely case that there's something bigger behind this behavior in babies.

Sandifer syndrome. This is a very rare condition that's often seen in babies with gastroesophageal reflux. Most babies with Sandifer syndrome exhibit unusual head movement, extreme back arching, and acid reflux. Some babies with this condition might also have non-typical eye movements or torticollis, when a baby's head tilts to one side because of neck muscle contractions.

Some signs of Sandifer could be mistaken for seizures. Sandifer is so rare that there's no official incidence rate, though it is estimated that less than 1 percent of babies diagnosed with GERD have Sandifer syndrome.

Cerebral palsy. Frequent back arching, especially if it seems to be without reason, can be a sign of cerebral palsy – but it's rarely the only symptom. Babies with cerebral palsy will also fail to meet developmental milestones within the expected timeframe. Children with cerebral palsy may have low muscle tone, making it difficult for them to roll over, sit up, and stand at the developmentally appropriate times.

Other early signs of cerebral palsy include feeling especially stiff or floppy while being held and being unable to bring their hands to their mouths or put their hands together by 6 months old.

If your baby regularly pushes away when you hold them, arches their back, and displays some of the signs mentioned above, share your concerns with their pediatrician. They can offer additional insight and guidance if they believe your baby should be screened for cerebral palsy.

Seizures. These often look like a rhythmic shaking of the limbs and are very different from an arch of frustration or discomfort. There's no confusing the two, as most seizures have very specific signs that are hard to miss.

Babies who are seizing will often become unresponsive, stare vacantly, or even lose consciousness. They may often jerk or twitch violently or their entire body will grow stiff and rigid. While it may be difficult to gauge in a baby, these symptoms will often be paired with the loss of bowel control.

Why your baby throws their head back

You may also notice your baby throw their head back when they arch their back. In babies younger than 2 months old, this can be a part of the Moro reflex. When startled by a loud noise, newborns instinctively throw their head back and quickly extend their limbs before pulling them back in toward their core.

Babies may also throw their head back in frustration alongside arching their back. In some cases, this could be a sign of autism. Specifically, repetitive head-banging can be an early sign of autism.

However, head-banging is also a common behavior among neurotypical babies, with roughly 20 percent of babies banging their head during their first and second year but growing out of it with time. If your baby is harming themself by throwing their head back or if you feel it's excessive, check in with their doctor to see if this could be a sign of an underlying developmental issue.

What to do when your baby arches their back

Whatever the cause, you'll want to be aware when your child begins hurling themself out of your arms, and take extra care when picking up your child in mid-arch. Very young babies will need you to support their head and neck, while older babies and toddlers will need your help avoiding injury. If they're sitting, they may hurl themselves backward and bump their head. You may need to move your baby to a safe place like their crib or the carpet.

If your baby is arching their back because they're upset, here are some ways you can help soothe them:

• Cover the basics: Is your baby hungry or in need of a diaper change? Look for signs they're cold, like cold hands or feet, and add more clothes. If they're red or sweating, take off a layer to help them cool down.
• If your baby is very young, swaddle them in a soft blanket and hold them securely. Sometimes turning them onto their left side while you hold them can soothe tummy troubles and help them digest.
• Walk around or gently bounce your baby while holding them.
• If your baby has recently eaten, feeding them again may make matters worse. Overfeeding can trigger reflux symptoms, so stick to their regular feeding schedule to avoid this.
• Use a sound machine or make a shushing sound to help soothe them. These noises will feel familiar and comforting to young babies.
• Try a change of scenery. Some fresh air and something new to look at can be surprisingly comforting to a cranky baby or toddler.

You know your baby best. If you think their back arching is concerning, or if it pairs with other worrisome signs, talk to their doctor. Your pediatrician can help you parse whether this is cause for concern and point you toward additional resources and solutions.