Why Babies Spit Up

Causes, Solutions, and When to Call the Doctor

It's normal for babies to spit up both breast milk and formula. Infants spit up after feedings (sometimes after every feeding) and often bring up some milk when they burp. This happens because babies gulp in air as they swallow, causing them to spit up the excess once their tummies get too full. If they still seem hungry after they spit up, you can keep feeding them, but likely they will have eaten enough.

Doctors may use the phrase "happy spitter" to describe a baby who spits up but is generally comfortable, has no breathing problems, and is thriving and growing well. According to the American Academy of Pediatrics, some babies seem more prone to spitting up than others, but if they don't seem to be in distress, it's not a cause for concern.

However, there are signs to look out for that might indicate that spitting up requires a doctor's evaluation. Learn what you can do to help prevent or reduce spitting up—and how to keep your baby comfortable.

Why Do Babies Spit Up?

Verywell / Nusha Ashjaee

What Causes Spit Up in Babies?

In newborns, the digestive system is still developing, so there is more spitting up in the first few months than later on. As babies feed, milk goes down the throat to the esophagus and then the stomach.

The esophagus is connected to the stomach by a ring of muscles called the lower esophageal sphincter. This sphincter opens to let the milk go into the stomach and then it immediately closes back up, but this "trap door" isn't as reliable as it should be until about 6 months of age when it is more mature. This can cause a backflow of milk that results in spit-up.

Aside from this, there are three primary reasons that babies spit up:

  • Overeating: Eating too much or too fast can be the culprit because babies have small stomachs. A baby who is taking too much milk at each feeding might fill up—and the extra milk that his belly can't hold has only one way to go.
  • Sensitivity or allergies to certain foods or drinks in your diet: Allergens can be transferred into breast milk and cause your baby to spit up.
  • Swallowing air during feedings: A baby who is drinking very quickly is also gulping air along with the milk. This is especially true if you have a strong let-down reflex or an overabundant milk supply.

GERD (A.K.A. Reflux)

For the babies that are not "happy spitters," spit-up may actually be caused by gastroesophageal reflux disease (GERD). If the lower esophageal sphincter doesn't tighten up immediately after it opens, the term "reflux" is used since the spit-up coming back up may be accompanied by stomach juices and acids.

Reflux can cause considerable discomfort in some babies. Symptoms of GERD include:

  • Gagging, choking, coughing, wheezing, or other breathing problems
  • Pain and discomfort
  • Poor growth due to vomiting (less common)

Discuss your baby's spit-up patterns with your pediatrician to figure out if GERD could be the culprit. If so, medication and other measures may be necessary.

Ways to Reduce Spit-Ups

There are several things you can do to decrease the likelihood or frequency of your baby spitting up.

Burp Your Baby

Try to burp your baby during and after each feeding to remove air from their belly. Some breastfed babies do not need to burp after every feeding, as they tend to swallow less air than bottle-fed babies.

However, if you have an abundant milk supply or a very fast flow of milk, that may not be the case. Sometimes babies spit up because they are burped. Still, this is a worthwhile measure to try.

Burping your baby helps to release any air swallowed during the feeding. After a burp, your baby will be more comfortable. Removing air may also make more room in your baby’s stomach to continue their feeding.

Keep Feedings Calm and Quiet

Try to limit distractions, noise, and bright lights while you are breastfeeding. Calmer feedings may lead to fewer spit-ups. Don't bounce or engage in very active play immediately following a feeding either.

Feed Your Baby Less Often

The American Academy of Pediatrics recommends waiting at least two and a half hours between feedings for formula-fed infants and at least two hours for breastfed infants. This is important to allow the stomach to empty before adding more milk to it.

Manage a Strong Let-Down

If you have a forceful let-down reflex, your milk may be flowing too fast for your baby. Try to nurse in a reclined position so that your baby is taking in the milk against gravity. You can also pump or express some milk from your breasts before beginning a feeding to help slow down the flow.

Experiment With Positions

Try different breastfeeding positions to see if some are more comfortable than others for your baby. And after a feeding, try to keep your baby's head upright and elevated for at least 30 minutes.

When to Call the Doctor

When your baby spits up, milk usually comes up with a burp or flows gently out of their mouth. Even if your baby spits up after every feeding, it is not usually a problem.

Vomiting is different. Vomiting is forceful and often shoots out of your baby’s mouth. A baby may vomit on occasion, and that's OK.

But if your child is vomiting repeatedly or for longer than 24 hours, and/or if the vomit is green or has blood in it, contact your healthcare provider. It could be a sign of illness, infection, or something more serious.

Other signs that it is time to call your baby's doctor includes concerns that your baby:

  • Appears to be in pain and is inconsolable
  • Does not keep feedings down and is showing signs of dehydration
  • Loses weight or is not gaining weight
  • Spits up too much or very often
5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Baird DC, Harker DJ, Karmes AS. Diagnosis and treatment of gastroesophageal reflux in infants and children. Am Fam Physician. 2015;92(8):705-14.

  2. American Academy of Pediatrics. Why babies spit up.

  3. Leung AK, Hon KL. Gastroesophageal reflux in children: an updated review. Drugs Context. 2019;8:212591. Published 2019 Jun 17. doi:10.7573/dic.212591

  4. American Academy of Pediatrics. Spitting Up - Reflux.

  5. Texas Children's Hospital. Why is my baby spitting up so much breastmilk?

By Donna Murray, RN, BSN
Donna Murray, RN, BSN has a Bachelor of Science in Nursing from Rutgers University and is a current member of Sigma Theta Tau, the Honor Society of Nursing.