Colic reportedly occurs in between 8 and 40 percent of newborns. Part of the reason for this wide range is that there is no standard definition of colic. However, most healthcare providers consider a baby to have it when he or she cries for more than three hours straight, at least three days a week for more than three weeks but is otherwise healthy. This is known as the "rule of three," or the Wessel criteria.
No one knows for sure what causes colic in newborns. Researchers have studied possible biological, social, psychological, and physical factors, but no single factor has been shown to cause it. Because babies with colic are otherwise healthy, it is not caused by a medical condition. The condition is also not caused by something that the parents are or are not doing.
You can take comfort in knowing that colic will not last forever. Typically speaking, the condition peaks around six to eight weeks and then goes away around the baby's third month (symptoms get better in 60 percent of newborns by three months and in 90 percent by four months). Colic often stops as mysteriously as it began.
(Click Infant Colic for a closer look at colic in newborns, including information on how this condition is diagnosed, possible risk factors, and tips on coping with it.)
