NCIt definition : Paroxysms of irritability, fussing or crying that starts and stops without obvious
cause in an infant up to four months of age without failure to thrive. Episodes last
three or more hours per day for at least three days per week for at least on week.;
Alternative definition : NICHD: Consistent pattern of crying in a healthy infant between 3 weeks and 3 months
of age. Often defined as lasting 3 hours a day more than 3 days a week for at least
3 weeks in a row.;