When to get help

Go to A&E or call 999 (in the UK) if your baby has a weak or high-pitched cry, or a cry that does not sound like their normal cry. That is the NHS instruction on its colic page.

Ask for an urgent GP appointment or call NHS 111 if arching comes with any of the signs on the NHS reflux page:

green or yellow vomit, or blood in the vomit;
projectile vomiting, or being sick over and over and unable to keep fluid down;
blood in the poo, or a swollen or tender tummy;
a very high temperature, or feeling hot, cold or shivery;
refusing to feed, or crying that will not stop with a baby who is very distressed.

NICE's reflux guideline adds a bulging soft spot and altered responsiveness, such as lethargy or irritability, to the red flags that point away from reflux and towards illnesses such as meningitis.

Stiffening in clusters is different. The American Academy of Pediatrics (AAP) describes infantile spasms, a form of epilepsy affecting about 1 in 2,000 children: the body stiffens suddenly, the back may arch and the arms, legs and head may bend forward. Each spasm lasts a second or two, they often come in a series every 5 to 10 seconds, and they are most common just after waking. They typically begin between 2 and 12 months. The AAP's advice is to talk to your doctor right away and to video an episode if you can.

See your GP if the arching is persistent rather than part of crying. NICE advises considering specialist assessment for babies with persistent back arching, or with features of Sandifer's syndrome: episodes of the head twisting to one side with the neck extended.

Why babies arch their backs

Arching is how a young baby shows distress, and on its own it does not point to one cause. The Royal Children's Hospital in Melbourne puts it plainly: drawing up the legs, back arching, going red in the face and intense screaming are all signs of distress, and they happen when young babies cry whether the reason is tiredness, hunger, or nothing obvious at all.

So the useful question is when it happens: during feeds, after them, in long evening crying spells, or when overtired.

Arching in long crying spells: colic

The NHS describes colic as crying more than 3 hours a day, 3 days a week for at least 1 week, in a baby who is otherwise healthy, often worse in the afternoon and evening. While crying, a colicky baby may clench their fists, go red in the face, bring their knees up to their tummy or arch their back, and their tummy may rumble. It usually stops by 3 to 4 months.

The NHS says anti-colic drops, herbal and probiotic supplements are not recommended because there is no evidence they help. It also advises against spinal manipulation and cranial osteopathy: there is little evidence they work, and they may hurt your baby. What it does suggest is holding your baby, feeding upright, winding after feeds and gentle rocking. More on colic and excessive crying.

Arching during or after feeds: reflux

Reflux is milk coming back up during or shortly after a feed. NICE says it affects at least 40% of infants, usually starts before 8 weeks and resolves in 90% before their first birthday. The NHS lists its signs as bringing up milk, coughing or hiccupping when feeding, being unsettled during feeding, swallowing or gulping after feeds, crying and not settling, and poor weight gain. Some babies have signs without bringing milk up, which is called silent reflux.

When reflux causes pain, it can show as arching. The Royal Children's Hospital lists irritability, crying a lot or arching the back among the signs of gastro-oesophageal reflux disease (GORD), along with disrupted sleep and poor weight gain.

Arching alone is not enough to call it reflux, though. NICE advises against routinely investigating or treating for reflux when a baby who is not visibly bringing milk up has only distressed behaviour. A GP may also consider cows' milk allergy, which the NHS says can look very similar.

The NHS self-help steps are to hold your baby upright during feeds and for as long as possible after, burp them regularly during feeds, and get advice on positioning. Your baby should still sleep flat on their back, and the NHS says not to raise the head of the cot or Moses basket. See reflux and posseting for the full picture.

Arching at the breast or bottle: wind and milk flow

The HSE describes wind as air swallowed during feeding, crying or yawning, and says it is common from birth to about 3 months. Signs of trapped wind are squirming or crying during a feed, and looking uncomfortable and in pain if laid down after a feed.

Its practical suggestions depend on how you feed:

Breastfeeding: check positioning and attachment, and ask your public health nurse or a lactation consultant to watch a feed. Hand expressing a small amount of milk before the feed can slow down the flow.
Bottle feeding: wind often during and after feeds, try a slower-flow teat, keep the teat full of milk, and hold your baby more upright rather than flat.

See winding and burping a newborn for positions.

Tongue tie

If arching comes with feeds that never seem to go well, tongue tie is worth asking about. The NHS lists the feeding signs as difficulty latching or staying attached, feeding for a long time and very often, dribbling, coughing, choking or clicking during feeds, taking only small amounts, and poor weight gain. Treatment ranges from feeding support to a small procedure; see tongue tie and breastfeeding.

Arching when overtired

Tiredness can look like discomfort. The Royal Children's Hospital lists early tired signs as jerky movements, frowning, clenched fists, yawning, staring and rubbing the eyes, and calls back arching, grizzling and crying late signs of being tired. If you see two or three tired signs, especially when your baby has been awake for a while, it suggests it is time for sleep. As a guide it gives 30 minutes awake for a newborn, or more than 90 minutes for a 3-month-old.

If the arching tends to come late in a long awake stretch, look at sleep timing first. See signs of an overtired baby and why babies fight sleep.

Frequently asked questions

Why does my baby arch their back while feeding?

The usual reasons are wind, reflux, feeding difficulties such as tongue tie, and tiredness. For wind, the HSE suggests checking attachment, hand expressing a little before breastfeeds to slow the flow of milk, or trying a slower teat. If arching is persistent, or comes with vomiting or poor weight gain, see your GP or health visitor.

Is arching the back a sign of reflux?

It can be, but not on its own. The Royal Children's Hospital lists back arching among the signs of painful reflux, yet NICE advises against routinely investigating or treating reflux when a baby without visible regurgitation shows only distressed behaviour. Arching also happens with colic, wind and tiredness, so the pattern around feeds matters more.

Why does my baby arch their back and throw their head back?

Usually it is the same distress response as crying, but two patterns need a doctor. NICE flags episodes of the head twisting to one side with the neck extended (Sandifer's syndrome). The AAP describes infantile spasms as sudden stiffening in clusters, often just after waking. Video either and get advice promptly.

Why does my baby arch their back when sleeping or lying down?

The HSE lists looking uncomfortable when laid down after a feed as a sign of trapped wind, so winding and holding your baby upright after feeds is the first step. Do not prop the cot: the NHS says babies with reflux should still sleep flat on their back. The AAP notes infantile spasms rarely occur during sleep.

Baby Arching Back