The baby sleep half of the sudden cry is mostly seen in inadequate feeding, urine and stool stimulation, the surrounding environment is noisy, lack of security and other physiological manifestations; also need to rule out pathological factors, such as dyspepsia, acute abdomen, vitamin D deficiency, etc., need to be analyzed on a case-by-case basis. 1. Physiological manifestations: insufficient feeding, urinary and faecal stimulation, noisy sleep environment, lack of security, etc. may cause sudden crying of babies during sleep, and the symptoms can be relieved after lifting the influencing factors. 2. Pathological factors: such as dyspepsia, abdominal distension, abdominal pain may cause crying at night; acute abdomen, such as intussusception, the baby crying with vomiting, bloody stools, you can check the abdominal ultrasound clear; vitamin D deficiency, the baby is often accompanied by night terrors, excessive sweating, occipital baldness and other conditions. The baby sleep half of the sudden cry, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.