What is Colic in Babies?

We expect babies to cry, but about 15 to 25 percent of newborns shed many more tears than others. When otherwise healthy babies cry excessively and inconsolably for no apparent reason, pediatricians might suspect colic. "It's not really a diagnosis; it's a behavioral observation," says Harvey Karp, M.D., creator of the DVD and book, The Happiest Baby on the Block. Read on to learn more about the causes and symptoms of colic, with tips on stopping the crying spells.

Colic is not a physical disorder or disease; rather, it simply refers to long periods of unexplainable crying. The condition is somewhat subjective, and whether your baby's crying is "average" or "excessive" may depend on how much you can endure. But many doctors use the "rule of three" description from pediatrician Morris A. Wessel, M.D.: 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. 

Nevertheless, you shouldn't get hung up on any official colic definition, says 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.  There is no blood test to confirm colic, and experts can't agree about the cause, treatment, or even the colic meaning. 

Colic starts around 2 to 3 weeks of age. A baby with colic will often go through his crying spells between 6:00 p.m. and midnight. Of course, that's 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. Colic usually peaks around 6 to 8 weeks and then slowly dissipates, disappearing completely around 3 to 4 months of age. 

Dr. Lester says 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, or being rocked. Colicky babies, on the other hand, suffer from unprovoked crying spells that don’t stop after soothing. 

“Colic is not the same kind of cry you'd get with 'I'm hungry,' or 'I'm dirty,' or 'I'm tired,'" says Parents advisor 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.”

Colic isn't a sign 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 a sign that your baby has belly pain, although the way she grimaces, clenches her body, arches her back, pulls her legs up, and screams till she's 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. (Dr. Karp calls this "the fourth trimester.") 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 causes 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 mom to be stressed out and anxious by the end of the day. Some experts believe the anxiety of a mother rubs off on her baby and causes the baby to be "stressed out" too.

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 Mom in utero, but levels drop after birth until the baby starts producing it on her 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."

Constant crying doesn’t always point to colic. Your baby 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 he's still crying inconsolably after 4 months. 

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

Milk-protein allergy: A milk allergy can develop if you're feeding a baby 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—a 2009 study from Italy found that a whopping 12 percent of all Italian babies met the official criteria. Unless the reflux is severe, Dr. Vartabedian suggests conservative measures like keeping your baby upright for 30 minutes after he eats or asking your doctor about a prescription acid-reduction medication.

If your baby's crying is incessant, no doubt you've already had several powwows with your pediatrician. "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, M.D., assistant professor of pediatrics at the University of Connecticut Health Center in Farmington.

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 and feeding, eczema, and lethargy. Keep a diary that tracks how often your baby cries, sleeps, eats, and poops and pees. Any difficulties with feeding or spitting up may help you discover if there's a pattern to the crying.

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."