The reason why 5-month-old babies wake up frequently at night is considered to be related to excessive hunger, urination and defecation, calcium deficiency factors, etc. You can consider timely feeding, changing diapers, calcium supplementation, etc. for relief. 1. Excessive hunger: for the 5-month-old baby, in the case of excessive hunger, it will cause the baby to wake up frequently in the night, so in the night before the baby goes to bed, you should let the baby eat enough, to avoid affecting the quality of sleep because of excessive hunger. 2. urination and defecation: after the baby urinates and defecates, the baby will also wake up frequently at night because of discomfort, and you need to change the baby’s diaper in time, which is conducive to the baby’s sleep. 3. Supplemental calcium: baby in the body of vitamin D deficiency, will affect the absorption of calcium, resulting in sympathetic nerve excitation, thus appearing to sleep frequently wake up the phenomenon, you can timely supplementation of vitamin D and calcium, is conducive to alleviate the symptoms. 5 months baby sleep frequently wake up at night there are other causes, it is recommended to timely medical treatment, cooperate with the doctor to carry out relevant examinations, clear specific causes before doing treatment and treatment.