One year old four months baby always crying at night what happened

One year old four months baby always crying at night, first of all, the baby mother did not breastfeed in time before bed, causing the baby to feel hungry after falling asleep. Secondly, excessive breastfeeding before bed, baby indigestion, can also cause the phenomenon, at the same time, such as baby iron deficiency, calcium deficiency and other trace elements, may also cause the phenomenon.