Five-month-old babies crying at breastfeeding may be caused by various factors such as insufficient milk, mouth ulcers, indigestion and so on. 1. Insufficient milk, if there is insufficient milk during breastfeeding to meet the baby’s needs, it may cause the baby to be more irritable and show symptoms of breastfeeding crying. 2. Mouth ulcers, some babies have mouth ulcers, oral mucous membrane damage, excessive force during the eating process may lead to pain symptoms, so there will be a baby breastfeeding crying symptoms. 3. indigestion, some babies have indigestion after food accumulation in the intestine can not be digested and absorbed, may appear bloating symptoms, so it will lead to the baby discomfort, produce breastfeeding crying reaction. Five-month-old babies crying for milk, there may be other reasons, it is recommended to go to the hospital, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.