Why Babies Spit Up and How To Help

Spit ups are one of the most common things new parents deal with, but they can be frustrating and even a little scary. You don't know why your little one is throwing up, or how to make it stop.
Have no fear! Although spit up might seem like a big—and messy!—problem at first, knowing what's causing it can help you manage the issue. In this article, we'll discuss why babies spit up, when to be concerned, and how you can minimize the mess.
In this article:
Typical appearance of spit ups
Likelihood of spitting up by age
Potential causes for baby spit ups
Immature digestive system/gastrointestinal tract
Too much activity right after a feeding
Swallowing too much air while feeding
Food intolerance or sensitivity
When to be concerned about spitting up
Gastroesophageal Reflux Disease
Hold your baby upright after feeding
Smaller, more frequent feedings
Q: My baby is spitting up a lot—should I be concerned?
Q: Is it normal for spit up to come out of my baby's nose?
Q: Why is my baby spitting up clear liquid?
Q: Why is my baby spitting up curdled milk?
Q: Should I worry that my baby isn't getting enough to eat if they spit up?
Q: Can spitting up cause Sudden Infant Death Syndrome (SIDS)?
What is spitting up?
“Spitting up” refers to a baby expelling small amounts of semi-digested milk or formula from their mouth or nose, usually soon after eating.
Babies tend to swallow air along with breast milk or formula and that air gets trapped in their stomach with the liquid. When the air comes up, some of the milk or formula comes up too, through either your baby's mouth or their nose.
It's common for infants to spit up and is usually not a cause for concern. In fact, almost half of young babies spit up regularly. In most cases, spitting up will slow down and eventually stop on its own as your baby's digestive system matures.
Typical appearance of spit ups
Baby spit up usually looks like the milk or formula that your baby recently drank. If your baby has started eating solid foods, their spit up may be slightly curdled or discolored, based on what they ate.
Consistency-wise, spit up can be thin and watery or much thicker, depending on what your baby ate and when.
The amount that a baby spits up can vary a great deal. Sometimes a baby spits up only a few drops, but other times they might spit up a larger amount that soaks their (or your!) clothes and requires an outfit change.
Spitting up vs. vomiting
Spitting up is different from vomiting, although both involve the contents of your baby's stomach being expelled from their mouth. The main differences between the two involve:
Force: When a baby spits up, the liquid generally just dribbles out of their mouth. Vomiting is much more forceful. In particular, projectile vomiting is when vomit shoots out of a babies mouth and should never be confused with spitting up.
Effort: Babies usually spit up passively and might not even realize that it's happening. Vomiting requires more effort and can even cause pain or discomfort.
Quantity: Spitting up is typically a small amount of liquid, while vomiting is usually a larger amount of liquid or food.
If your baby vomits frequently or forcefully, you should seek immediate medical attention.
Likelihood of spitting up by age
Spitting up is most common in young babies and typically begins around two to three weeks.
It typically peaks around four to five months of age and begins to decrease in frequency after six to eight months.
Most babies will have stopped spitting up by their first birthday. However, some babies may continue to spit up occasionally even after they turn one.
Incidence of daily regurgitation between one and twelve months of age

Source: Curien-Chotard M, Jantchou P. Natural history of gastroesophageal reflux in infancy: new data from a prospective cohort. Used with permission via Creative Commons license.
How frequently does your baby spit up?
More than six times per day
Four to six times per day
One to three times per day
Rarely or never
Potential causes for baby spit ups
There are numerous reasons why even healthy infants may spit up regularly.
Immature digestive system/gastrointestinal tract
Newborn babies' digestive systems are not yet fully mature (the reason why they can't eat solid foods until around six months). This can contribute to discomfort and spitting up in several ways.
Most importantly, their esophageal sphincter, the muscle at the end of the esophagus that closes to keep out stomach contents, is underdeveloped. This makes it much easier for swallowed milk or formula to come back up–their stomach is like a bottle with no cap!
Second, a newborn's stomach and intestines can't yet digest complex sugars and proteins, which can cause difficulty in digesting certain foods and contribute to spit ups.
A baby's digestive system is generally considered to be fully mature by their first birthday.
Too much activity right after a feeding
Just like yours, your baby's tummy needs a little time to settle after eating. It's best to wait 30 minutes or so before doing tummy time, bouncing, or anything else energetic!
Swallowing too much air while feeding
Swallowing too much air while feeding can cause gas and discomfort. To avoid this, make sure that you are holding your baby upright for feedings.
If you are bottle-feeding, hold the bottle at a 45-degree angle or less to ensure that the nipple is always filled with milk/formula.
Consider using a bottle that is designed to reduce air intake, such as a vented bottle or an angled bottle.
Eating too quickly
If a baby eats too quickly, they are more likely to swallow air, as well as overeat.
If you are bottle-feeding, make sure to use a bottle nipple with the correct flow rate for your baby's age and development. An overly fast flow can make your baby gasp or choke and swallow air.
Food intolerance or sensitivity
Breastfed babies
The foods that breastfeeding mothers eat can contribute to their baby's digestive discomfort and spitting up.
Just like grown-ups, some babies may be more sensitive to the effects of certain foods in breast milk than others. Unlike allergies, this type of reaction tends to be minor and temporary, so your baby will likely become less sensitive over time.
If you think that your baby could have an intolerance or sensitivity to something that you eat or drink, you can try eliminating certain items from your diet for a time to see if it helps. Just check with your own physician and your baby’s pediatrician before eliminating any foods.
Formula-fed babies
Most babies can easily digest cow's milk formula with no adverse reactions. However, 1-2% of infants are allergic to the proteins in cow’s milk and require special formula. Of these babies, up to 50% are also sensitive to soy protein and require an even more specialized formula.
Always consult with your healthcare provider before eliminating foods from your diet or switching formulas. They can provide guidance and rule out other possible causes for your baby's discomfort.
For more information about baby formula, check out The Basics of Baby Formula.
Digestive condition
Almost all healthy babies have some degree of infant acid reflux, also known as gastroesophageal reflux (GER), which manifests as fussiness, gas, and spitting up.
If these symptoms occur frequently or your baby seems to be in pain, consult with your doctor. Your baby may have a more serious form of acid reflux called gastroesophageal reflux disease (GERD), discussed in more detail below.
When to be concerned about spitting up
As annoying as it can be to put yet another spit up-stained onesie in the laundry, keep in mind that some degree of spitting up is normal in healthy babies. It is not usually a cause for concern unless the spitting up is excessive or accompanied by other symptoms that could indicate a more serious problem.
Symptoms to watch for
Poor weight gain or weight loss
Coughing or breathing difficulties
Spit up that is green or yellow, contains blood, or looks like coffee grounds
Frequent crying (more than usual fussiness)
Refusing to eat for multiple feedings
Fewer wet diapers—this could be a sign of dehydration
If your baby is experiencing any of these symptoms, you should seek immediate medical attention.
Gastroesophageal Reflux Disease
Gastroesophageal reflux disease (GERD) is a condition in which stomach acid and other stomach contents flow back into the esophagus, causing discomfort and irritation. It is a chronic and much less common form of the type of infant reflux that many babies experience.
The following graph compares the prevalence of GERD versus regular infant reflux (GER).
Incidence of GER and GERD between one and twelve months of age

Source: Curien-Chotard M, Jantchou P. Natural history of gastroesophageal reflux in infancy: new data from a prospective cohort. Used with permission via Creative Commons license.
Just like GER, GERD in babies is usually caused by a weak or immature lower esophageal sphincter, the muscle at the end of the esophagus that is supposed to close during regular digestion. This is more likely to occur in babies born prematurely.
Symptoms of GERD in babies can include:
Frequent spitting up
Difficulty swallowing
Crying or fussiness during and after feedings
Repeated feeding refusal
Poor weight gain
Arching of the back or neck during or after feedings
Coughing or wheezing
GERD can be very uncomfortable for babies, but it is rarely considered dangerous.
However, it can occasionally cause complications such as failure to thrive or breathing problems, so don't disregard the symptoms.
If your baby is experiencing symptoms of GERD, it's important to consult a pediatrician to develop an appropriate treatment plan.
How to reduce spitting up
There are several ways that you can reduce the frequency and quantity of your baby's spit up.
Hold your baby upright after feeding
After feeding, hold your baby in an upright position for 20 to 30 minutes. This will help the milk or formula settle in their stomach.
Burp your baby
Make sure to burp your baby during and after feedings to release any trapped air. Depending on your baby's age and feeding style, you may need to burp them even more frequently.
To learn more about burping, see Burping Babies: How You Can Ease and Prevent Discomfort.