Baby crying at night may be related to physiological factors, or may be caused by indigestion, rickets and other reasons. 1. Physiological factors: for example, the sleep environment in which the baby is too noisy, easily awakened, or due to stomach hunger, urination, defecation, resulting in discomfort, etc., may cause the baby to cry at night. 2. Indigestion: If the baby has improper diet, such as overeating, eating a lot of cold, stimulating, indigestible food, etc., may exceed the baby’s gastrointestinal tract’s digestive capacity, resulting in indigestion, causing bloating, abdominal pain and other gastrointestinal discomforts, which may show the phenomenon of crying at night. 3. Rickets: some babies due to severe lack of vitamin D, rickets, leading to increased nerve excitability, resulting in restless sleep, there may be night crying phenomenon, may also be accompanied by excessive sweating, occipital baldness and other manifestations. Baby crying at night, there may be 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.