How do we know what a baby is crying about?

I can't presume to have the answer, but I have collated some pointers into a checklist I can run down each time I hear a fussy baby. This list is also a chronological list that comes after the start of a feeding-waking-sleeping cycle.

1. Gassy tummy - go burp the baby.
2. Dirty diapers - go change the diapers.
3. Wanting attention - go hold the baby, cradle him/her.
4. Over-fed - hold the baby vertically; reduce the feeding frequency and volume.
5. Hungry - go feed the baby.

Hungriness should always be the last priority, and should be used only when enough time has elapsed, such that we are close to the next feeding cycle. Otherwise, we risk over-feeding.

Be aware: Burping can take up to 20 minutes or so. 5 minutes might not be enough.

Depending on the child, you might need to hold him/her for close to an hour before they'll go to sleep.