“The vast majority of babies will spit up regularly, especially in the first few months of life,” says Rebekah Diamond, MD, a pediatric hospitalist in New York City and Assistant Professor of Pediatrics at Columbia University. “The reason that babies spit up so much is that their lower esophageal sphincter isn’t well developed, and this is the muscle that our bodies use to keep food from going back from our stomachs to our esophagus.” Spitting up is usually no big deal for your baby and something they’ll outgrow with time. But some types of spit-up could signal a health concern. Here’s how to recognize the difference between normal spit-up and abnormal spit-up along with tips for getting help if needed.

What Is Normal Spit-Up?

While all babies differ slightly in their digestion habits, there are a few characteristics shared by most “happy spitters”—infants who aren’t bothered by spit-up. “Normal baby spit-up looks and smells pretty much like milk,” says Dr. Diamond. “It’s a light or whitish color and can have clumps of digested milk in it. It doesn’t smell quite as mild or pleasant as actual milk but it tends not to have the strong, unpleasant smell of older people’s vomit.” Normal spit-up amounts can vary widely, from a few dribbles down a baby’s onesie to a total soaking of your shirt sleeve. If your baby seems comfortable and is growing properly, the fact they bring up a lot of milk between meals probably isn’t a cause for concern. “Some babies spit up a lot—once or even more with every feed. So much depends on the individual baby,” says Dr. Diamond.

What Is Abnormal Spit-Up?

Even though watching your baby “lose” milk after many or most feeds may be distressing, there’s probably little need to worry if their spit-up quality and quantity are consistent. But there are a few signs that your baby’s spit-up habits may signal a problem with their growth or health. Note that if your baby is projectile vomiting, this may be a sign of pyloric stenosis, or a blockage in their stomach. You should see a healthcare provider immediately.

Changes in Color

The color of your baby’s spit-up may vary slightly from day to day, but not much. “For the most part, it should be that light white, cream, or yellowish color and not have too many other tints in it,” says Dr. Diamond. A color you don’t want to see is green. “Dark green spit-up can mean that there’s something blocking milk from going down the intestines,” explains Dr. Diamond. Bright green or yellow colors can also be a concern. “This is what bile looks like and this can be worrisome in babies,” says pediatrician and lactation consultant Neela Sethi, MD, a MAM Baby ambassador. Vomiting bile can be a sign of severe gastroesophageal reflux disease (GERD). Red or black are other colors that can throw up flags because they can indicate there’s blood in spit-up. Your baby could have bleeding in their digestive tract, another possible sign of serious GERD that warrants a call to your baby’s pediatrician.

Excessive Volume

Since normal spit-up volume can change significantly from baby to baby, it’s tricky to identify this problem on your own. “It does seem like your baby is spitting up the ’entire bottle’ but this is usually not the case,” says Dr. Sethi. “It is usually much less than the baby consumed.” The surest way to figure out if your baby is spitting up too much milk is by making regular appointments with your baby’s pediatrician to assess how your baby is growing. If your baby isn’t growing steadily, they may be regurgitating more milk than is healthy. If your baby is dehydrated it can also be a sign that they are spitting up too much. Common signs of dehydration in babies include less urinating, fewer tears when crying, and a dry, parched mouth.

Distress When Spitting Up

When adults vomit, it’s unpleasant and uncomfortable. That’s not usually the case for babies. “Milk is mild and even though babies regurgitate all of the time, it usually doesn’t cause much discomfort,” says Dr. Diamond. But if your infant is an “unhappy spitter,” something could be wrong. “If babies are consistently fussy when they spit up, it might be GERD or milk-protein intolerance,” explains Dr. Diamond. Some babies are sensitive to cow’s milk protein, leading to fussiness and colic symptoms when they take milk in (or bring it back up). Eliminating all sources of dairy from your diet if you’re breastfeeding or switching formulas may reverse these issues.

When to See a Doctor About Spit-Up

If your baby starts spitting up odd colors or excessive amounts, reach out to a doctor. “You should also see your pediatrician if your baby seems fussy with feeds, starts consuming less volume per feed, starts arching their back during feeds, or just seems to not enjoy eating at all,” says Dr. Sethi. When it comes to your baby, Dr. Diamond stresses that no problem is too small to seek help. “Even if you don’t know if it’s a problem but just feel worried, contact your on-call pediatrician or make an appointment to talk through it. We love to chat,” she says.

A Word from Verywell

Spitting up is completely normal behavior in babies, especially ones younger than six months old. Usually, spitting up won’t bother your little one and should be nothing more than a minor nuisance to you. (That’s why we stock up on burp cloths!) However, take note of any concerning changes in your baby’s spit-up patterns, and don’t hesitate to share them with a pediatrician. Keeping track of all aspects of your baby’s feeding cycle helps ensure they are healthy and happy as they grow.