The reasons why newborns cry and can’t sleep well include physiological factors such as environmental discomfort and pathological factors such as vitamin D deficiency. 1. Physiological factors: for example, the temperature is too high or too low, the quilt cover is too thick or too thin, eat too much, eat too little, urine and feces are not handled in a timely manner, etc., the newborns will be uncomfortable, there will be a crying and sleep, this time, we should check the situation of the newborns in a timely manner, to take the appropriate measures to relieve the discomfort. 2. Pathological factors: for example, vitamin D deficiency rickets will lead to increased neuromuscular excitability, there will be crying; respiratory tract infections, gastrointestinal diseases such as acute gastroenteritis, newborns will be due to fever, abdominal pain and other discomforts, will also be uncomfortable, in which case the newborns will also be crying. Newborns cry and sleep, there may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.