Some of the causes of sudden crying at night in pediatric sleep include hunger, shock, urination and defecation, and calcium deficiency. The measures to be taken are different for different causes of crying in pediatrics. The methods taken are feeding, removing frightening factors, changing diapers, calcium supplementation and so on. 1. Hunger: When the baby appears to be hungry at night, due to the instinctive reaction of foraging for food, the baby will cry. Parents need to feed food in moderation, but do not overfeed and aggravate the burden on the stomach. 2. Frightened: If the baby sleep suddenly hear violent sounds or skin is strongly stimulated will be frightened, beyond the baby’s organism to accept the ability, will express their emotions through sudden crying. Parents need to move away from the stimulation of the baby objects, or to a quiet environment to patiently calm the baby. 3. urination and defecation: baby skin tissue is sensitive, fragile, when defecation and defecation, wet diapers or pads will stimulate the baby’s skin, resulting in discomfort, sudden crying. Parents found, need to change in time. 4. Calcium deficiency: baby if calcium deficiency, easy to cause increased nerve excitability, may also lead to children suddenly cry at night, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor to supplement calcium and vitamin D to alleviate the symptoms. When a child suddenly cries in his sleep at night, parents must carefully observe the baby’s reaction, to rule out physiological factors, the baby is still crying, it is recommended to go to the hospital.