It may be due to digestion problems or a sensitivity to something in the baby's formula or that a nursing mom is eating. Or it might be from a baby trying to get used to the sights and sounds of being out in the world. Some colicky babies also have gas because they swallow so much air while crying.

Is it colic or colicky?

What are the symptoms of colic? A healthy baby may have colic if he or she cries or is fussy for several hours a day, for no obvious reason. Colicky babies often cry from 6 p.m. to midnight. Colicky crying is louder, more high-pitched, and more urgent sounding than regular crying.

How long has colic been around?

A 1954 paper on infantile colic, or “paroxysmal fussing,” first used the now-common definition: Colicky babies are otherwise healthy but spend more than three hours a day crying, on more than three days a week, for longer than three weeks.