Colic is excessive crying behavior in a baby between 3 weeks and 3 months of age. During a crying episode, a colicky baby may cry loudly and continuously, be hard to console, get red in the face, clench the fists, and arch his or her back or pull the legs up to the stomach.

Doctors generally diagnose colic when an otherwise healthy baby cries for more than 3 hours a day more than 3 days a week for at least 3 weeks, and with greater intensity than is typical for the age. The cause of colic is not known. Evidence suggests that colic results from a combination of a baby's sensitive temperament, environment, and immature nervous system. These factors can make a baby cry easily and have difficulty stopping after he or she has begun. As babies grow and develop, they are better able to regulate crying behavior.

Symptoms of colic occur most often in the late afternoon and evening hours. And the amount of crying may vary from day to day. Colic sometimes is relieved by calming the baby's environment, talking or singing softly, or taking the baby for a walk or drive. Colic is usually worst when babies are around 6 to 8 weeks of age. It usually goes away on its own by approximately 3 months of age.