More than seven months baby crying at night, common causes include: physiological reasons, vitamin D deficiency, gastrointestinal dysfunction and so on. 1. Physiological reasons: the baby’s sense of security is poor at night, often cry more than during the day, but the baby’s spirit, appetite, growth and development is good, not accompanied by other discomforts, parents can strengthen the appeasement. 2. Vitamin D deficiency: Vitamin D deficiency when the baby’s mental hyperactivity, irritability, there may be increased night crying, often accompanied by occipital baldness, excessive sweating, growth retardation, delayed closure of fontanel, and so on. 3. Gastrointestinal dysfunction: may be due to increased peristalsis, flatulence leading to abdominal discomfort, the baby crying at night increased, often accompanied by abdominal distension, diarrhea, vomiting and other symptoms. More than seven months of the 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.