Infants who wake up crying in their sleep may be hungry, frightened, etc., or they may be suffering from vitamin D deficiency or other health problems such as abdominal pain. Suddenly waking up from crying during sleep may be due to hunger, which will usually stop after feeding and continue to sleep. In addition, infants are also more sensitive to changes in the surrounding environment. When the surrounding environment is noisy, infants are easily startled, thus waking up crying in their sleep. In addition, if a baby’s vitamin D deficiency is severe, he or she may suffer from rickets, in which case the child will often wake up at night, cry, and sweat excessively. In addition to rickets, if the baby has abdominal pain, fever, nasal congestion and other physical symptoms, may affect the baby’s sleep, so that the baby wakes up crying. There may be other reasons for babies to wake up crying in their sleep, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.