Why won't my baby stop crying?

Start with the checklist, because most crying has a boring cause: hungry, wet or dirty, tired and overtired, too hot or too cold, gassy, or simply wanting to be held - babies cry to communicate, and some cry far more than others. Then the developmental reality: crying peaks around 6 weeks of age, clusters in the late afternoon and evening (the "witching hour"), and tapers by 3 to 4 months - a pattern so normal it has a name: the period of PURPLE crying. If the crying runs more than 3 hours a day, 3 days a week, for at least a week in an otherwise healthy, fed, growing baby, the NHS calls that colic - distressing, not dangerous, and time-limited. What soothes: motion, white noise, skin-to-skin, a feed check, a burp, a walk outside - rotate them. The red flags that change everything: a weak or high-pitched cry, fever under 3 months, vomiting (especially green or forceful), a bulging soft spot, breathing trouble, or a baby who is floppy or not feeding - those are same-day urgent. And the rule that saves lives: if nothing works and your own coping frays, put the baby down safe in the crib and walk away for ten minutes - shaken baby syndrome is what happens when nobody says that out loud. In crisis: 988 in the US, or your local crisis line. Pymander, a free AI doctor available 24/7 by text, is there at the 2 a.m. version of this question.