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 every feeding) and often bring up some milk when they burp. 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.

Despite this just being one of those things babies do, there are things you can do to help prevent it and keep your baby comfortable. There are also signs to look out for that might indicate that spitting up requires a doctor's evaluation.

Why do babies spit up?
Verywell / Nusha Ashjaee

Why Babies Spit Up

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 distinct reasons that babies 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.
  • Overeating can be a 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: These allergens can be transferred into breast milk and cause your baby to spit up.

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:

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

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 her 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.

When you burp your baby, you are helping release the 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 the feeding.

Sometimes babies spit up because they are burped. Still, this is a worthwhile measure.

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 More Often

If you wait too long between feedings and your baby is very hungry, she may feed too quickly and take in excess air. Stick with the same recommended quantity of milk over the course of a day, just consider adjusting your feeding schedule.

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.

Relieve Engorgement Before Feeding

If you have too much milk or your milk supply has not yet adjusted to your baby’s needs, your breasts might be engorged. This can make your breasts full and hard, making it difficult for your baby to latch properly and get a good seal around your nipple. As a result, your baby will take in air as he tries to nurse.

Use a pump or express some milk before feeding your baby to soften the breast. This will help your baby to latch on properly.

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 his 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 pediatrician. It could be a sign of illness, infection, or something more serious.

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

  • You are concerned that your baby is spitting up too much or too often
  • The baby appears to be in pain and is inconsolable
  • The baby is losing weight or not gaining weight
  • The baby is not keeping down any feedings and is showing signs of dehydration
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Article Sources

  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. 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

Additional Reading

  • American Academy of Pediatrics. Your Baby’s First Year. 3rd ed. New York, NY: Bantam Books; 2010.