A Parent's Guide to Colic in Babies

We expect babies to cry—it's pretty much a given, and a part of being a new parent. But when otherwise healthy babies cry excessively and inconsolably for no apparent reason, pediatricians might suspect colic, which can start as early as two to three weeks after birth.

If you're wondering if your baby might have colic, read on to learn more about this condition, the signs and symptoms, and when to contact a health care provider with your concerns.

What Is Colic?

Colic is not a physical disorder or disease; rather, it simply refers to long periods of unexplained crying that are difficult to comfort. The condition is somewhat subjective, and whether your baby's crying is "average" or "excessive" may depend on your expectations and how much you can endure. But many doctors use the "rule of three" description, established by esteemed pediatrician Morris A. Wessel, M.D., which essentially is this: Healthy babies who cry for more than a total of three hours a day, for more than three days a week, for more than three weeks, might have colic.

It's important to know that colic is extremely common, with research suggesting it affects approximately 20% of babies worldwide.

When Does Colic Start?

Colic tends to start around 2 to 3 weeks of age. Colic usually peaks around 6 to 8 weeks and then slowly dissipates, disappearing completely around 3 to 4 months of age. A baby with colic will often go through their most intense crying spells between 6:00 p.m. and midnight. Of course, that's usually just when you as a parent are also feeling worn out. While the incessant screaming might make you want to pull your hair out, just remember that this phase won't last forever.

Signs of Colic in Babies

The main symptom of colic in babies is prolonged, inconsolable crying. According to Barry Lester, Ph.D., director of the colic clinic at the Brown University Center for Children at Women & Infants Hospital in Providence, and coauthor of Why Is My Baby Crying, the colic symptom checklist includes the sudden onset of a high-pitched, screechy "pain cry" and inconsolability. Other signs include an enlarged stomach, passing more gas than usual, and extending/pulling up the legs.

What's the difference between normal crying and colic? With normal crying, the wails are usually related to a need (feeding, holding, changing, etc), and come in no particular pattern throughout the day and night. Fussy babies tend to calm down with cuddling, being held, being sung to, or being rocked. Colicky babies, on the other hand, suffer from unprovoked crying spells that don't stop after trying soothing techniques.

"Colic is not the same kind of cry you'd get with 'I'm hungry,' or 'I'm dirty,' or 'I'm tired,'" says Jennifer Shu, M.D., coauthor of Heading Home With Your Newborn. "With a hunger cry, babies feel better when you feed them. With colic, you don't know what your baby wants."

What Causes Colic in Babies?

Colic isn't a sign that you're not taking good care of your baby or that your baby is sick, although things such as reflux, food allergies, and exposure to cigarette smoke can cause further aggravation and tears. Nor is it necessarily a sign that your baby has belly pain, although the way they grimace, clench their body, arch their back, pull their legs up, and scream till they're purple can make it seem so.

What causes colic—and why some babies experience it and others don't—remains a mystery. Here are some theories:

Overstimulation

Some doctors view colic as a natural developmental stage as babies adjust to all the different sensations and experiences that come with life outside the womb. After being awake for hours trying to absorb all the sights, sounds, and smells of the world, babies may reach their limit and cry out.

Digestive issues

Some babies suffer from enlarged stomachs or increased gas during their crying spells, leaving some experts to believe gas pain contributes to the screaming. Excessive gas can be caused by lactose intolerance, an allergy to milk, or gas-producing foods passed through the breast milk, such as caffeine, nuts, or some vegetables. Infant acid reflux may also cause digestive issues.

Conveyed anxiety

It's not unusual for a new parent to be stressed out and anxious by the end of the day. Some experts believe the anxiety of a parent can rub off on their baby and causes the baby to be "stressed out" too. However, it's important to consider that caring for a colicky baby is inherently stressful—and colic happens to babies with parents who don't feel overly stressed, as well.

Chemical imbalance

Yet another theory is that colic stems from an imbalance of the brain chemicals melatonin and serotonin. Colicky babies might have more serotonin, which makes the intestinal muscles contract, says Marc Weissbluth, M.D., professor of clinical pediatrics at Northwestern University School of Medicine and author of Your Fussy Baby. One reason colicky babies can fuss more at night, he explains, is that serotonin levels peak in the evening.

This imbalance, the theory goes, naturally resolves when babies start making melatonin, which relaxes intestinal muscles. Babies get ample melatonin from their parents in utero, but levels drop after birth until the baby starts producing it on their own at 3 to 4 months—interestingly, around the same time that colic typically disappears. "This hypothesis should reassure mothers that they didn't cause colic," Dr. Weissbluth says. "It takes away the guilt that you're doing something wrong and aren't able to soothe your baby."

Is It Colic or Something Else?

Constant crying doesn't always point to colic. Be sure to check with your pediatrician to rule out any medical issues that could be causing your baby's crying. They might have an underlying medical condition (such as constipation, allergies, reflux, a hernia, or a urinary tract infection) that remains to be diagnosed—a strong possibility if they're still crying inconsolably after 4 months.

Constipation

Your baby may be fussy because they are straining to eliminate hard stools, says Bryan Vartabedian, MD, author of Colic Solved. Don't worry too much about how many hours or days have passed since their last dirty diaper; constipation is defined more by effort than by time, he explains.

Milk-protein intolerance

A milk intolerance can develop if you're feeding a baby cow milk-based formula, or if you're nursing and consuming dairy. It tends to peak two to four weeks after a child is born. Babies who suffer from it typically have mucus or red streaks of blood in their stool and cry a lot. They also may develop a dry, scaly rash anywhere on their face or body, says Dr. Vartabedian.

Gastroesophageal reflux

Reflux, or excessive spitting up, may play a role in some inconsolable crying. Reflux is fairly common in babies—and typically resolves on its own after a few months. Unless the reflux is severe, Dr. Vartabedian suggests conservative measures like keeping your baby upright for 30 minutes after they eat or asking your healthcare provider about a prescription acid-reduction medication.

When to Call a Health Care Provider

While colic is common, if you have concerns, it's always important to reach out to a pediatrician or health care provider. "Even though colic is normal, it's not something you should keep quiet about, because there will be babies who do have something else," says Larry Scherzer, MD, assistant professor of pediatrics at the University of Connecticut Health Center in Farmington. Additionally, you may benefit from extra support, as coping with a crying baby is no easy feat.

Apart from fussiness, additional red flags that could indicate a more serious medical condition include frequent vomiting, fever, loose or bloody stools, poor weight gain, difficulty with feeding, eczema, and lethargy. Keep a diary that tracks how often your baby cries, sleeps, eats, poops, and pees. Any difficulties with feeding or spitting up may help you discover if there's a pattern to the crying.

How Colic Affects New Parents

Although it's not harmful in itself, colic can still take its toll. For starters, it puts terrible pressure on new parents. "It sent my husband and me into therapy," confesses Catherine McManus, a mom from Oviedo, Florida. Excessive crying is also associated with giving up breastfeeding, overmedication of babies, postpartum depression, and shaken-baby syndrome.

Colic is nerve-racking, but it's helpful to remember that it's also temporary. "Colic is not your baby's defining personality trait," says Laura Jana, M.D., coauthor of Heading Home with Your Newborn (American Academy of Pediatrics). "Once the colic is gone, your child can have a completely different personality–spunky, sensitive, crabby. But colic is not going to tell you which, because it doesn't carry over."

The Bottom Line

Having a colicky baby is a challenge for even seasoned parents. Health professionals aren't even sure exactly why it happens or how to soothe these babies. Rather, it's something that parents and their babies just need to get through.

Ultimately, having colic is not a reflection of your baby's health or temperament—or your ability or dedication as a parent. And while it's hard to imagine while you're in the thick of their inconsolable crying spells, soon enough, your baby will be all smiles and you'll be enjoying much more relaxed—and quieter—evenings and nights with your little love.