Whether it is normal for a 50-day-old baby to sleep 6 hours at night without waking up needs to be decided according to the baby’s mental state and the amount of breast milk consumed, as analyzed below: 1. Normal situation: if the baby is not a regular occurrence of 6 hours of sleep at night, and the state of mind, the amount of milk are normal, and there is no other discomfort, generally do not have to worry about, may be the baby during the day to play more tired caused by waking up to eat the milk, and continue to observe can be. 2. abnormal situation: if the baby regularly sleeps 6 hours at night, or also accompanied by reduced milk intake, depression and other conditions, may be related to neonatal sepsis, ischemic-hypoxic encephalopathy, anemia and other pathological factors, the need for further to the hospital to carry out the relevant examination. There may be other reasons for a 50-day-old baby to sleep for 6 hours at night without waking up. It is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.