Children waking up crying all the time is usually caused by physiological discomfort, indigestion, vitamin D deficiency and other factors. 1. Physiological discomfort: children wake up crying all the time, may be due to wake up hungry, or sleeping process, diaper wetting the diaper, resulting in children feel uncomfortable, wake up crying all the time. In addition, if the child is in the environment temperature is too high or too noisy, will affect the child sleep, resulting in children waking up crying. 2. Indigestion: Children who eat too much indigestible food before bedtime are prone to indigestion, resulting in abdominal pain, bloating, belching (burping), acid reflux and other symptoms, children may wake up crying due to abdominal pain. 3. Vitamin D deficiency: the lack of vitamin D in the child’s body will make the child irritable, sleep disturbance, excessive sweating and other symptoms, thus affecting the quality of their sleep, waking up crying phenomenon. Children wake up crying all the time may also have 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.