My baby since birth was not a crying baby. He used to cry but it was feeble and very short, that too only when he was hungry or sleepy. But since 4th month, he has started crying loudly and for longer durations. He cries often during the nighttime even when he is full. He cries daily during the night time when he’s asleep. He cries very loudly and doesn’t stop soon even after rocking and soothing him with comfort. He cries rarely or never during the day time. Should I be concerned about his new crying behaviour? Or is it something that causes him too much pain? What can be done to address his problem.