Why Do Babies Vomit?

This is a really common question from many parents. After all, it can be scary to see your baby vomit. It can look like a lot of vomit for such a small baby too! So how do you know what is normal?

My baby is vomiting – should I be worried?

Many parents can be concerned when their baby is vomiting. Most babies vomit at some time, and usually, this is nothing to worry about. When babies are small the muscle at the top of their stomach, known as the sphincter, is loose and can open easily, causing your baby to vomit. This type of vomiting is often referred to as “spitting up” or “positing.” Nearly all babies will “posit” and spit up a bit of excess milk. It can often happen when you pick them up from breastfeeding and the movement causes any excess milk to spill over and come out!

It is normally only a little bit of milk, likely just a few millilitres and will cause baby no problems. Even though it is a small amount it can look like a lot and this understandably get parents worried. But try not to worry! Most vomiting is in the realms of normal, despite what it may look like!

What about reflux?

Reflux is very common in babies. It is estimated that 40 to 60 per cent of newborns experiences some degree of reflux for the first few months. Reflux can cause discomfort and pain to babies due to the irritation of stomach acid in the oesophagus. Most babies may outgrow reflux and may not require medical intervention, but for some, it can lead to other health complications.

Reflux occurs when the milk in the babies stomach passes back up into a baby’s oesophagus. In the stomach, there is hydrochloric acid which helps aid the digestion of milk, and when it is refluxed it can cause discomfort, pain and damage to the oesophagus.

Reflux is equally common in formula-fed and breastfed babies, but formula-fed infants have episodes of reflux more often than breastfed babies and the episodes last longer.

Understanding the Warning Signs When it Comes to Vomiting

There are some rare vomiting patterns which if you think your baby is doing should be investigated by your baby’s GP or paediatrician:

  • Projectile vomiting – is baby vomiting where it flies out of their mouth and lands a fair distance away from them
  •  If your baby is losing weight or not gaining weight efficiently
  • If the vomit is any colour other than milk colours; i.e. green, red, orange
  • If there is blood in your baby’s vomit
  • If your baby is showing signs of discomfort or pain
  • If your baby coughs after feeds
  • If your baby has a temperature

If your baby is vomiting occasionally but is otherwise content, happy, growing well and gaining weight according to the child health growth charts and is breastfeeding as per usual then the vomit you’re seeing is likely nothing to be concerned about.

If your baby’s vomiting pattern changes or you notice any of the signs highlighted above or if you are worried, follow your instincts, and seek professional advice from your GP or Health Care Practitioner.






1. Hegar B, Dewanti NR, Kadim M, Alatas S, Firmansyah A, Vandenplas Y 2009, Natural evolution of regurgitation in healthy infants. Acta Paediatrica 98(7):1189-1193

2. Parilla Rodriguez AM, Davila Torres RR, Gonzalez Mendez ME, Gorrin Peralta JJ 2002, Knowledge about breastfeeding in mothers of infants with gastroesophageal reflux. Puerto Rico Health Sciences Journal 21(1):25-29

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