One-year-old baby waking up frequently at night crying, may be related to environmental factors, may also be due to indigestion, vitamin D deficiency rickets and other reasons. 1. Environmental factors: a year-old baby if the sleep environment is not good air circulation, indoor temperature is too low, too high, or too much noise, etc., are prone to lead to the baby sleep is not stable, so that the performance of the night waking up frequently crying. 2. indigestion: one year old baby if the diet is not regular, regular overeating, easy to lead to indigestion, resulting in gastrointestinal dysfunction, resulting in abdominal distension and discomfort, may cause frequent waking up at night and crying. 3. Vitamin D deficiency rickets: If parents fail to give the baby reasonable supplementation of vitamin D and calcium, coupled with the baby’s poor dietary habits, resulting in insufficient nutrient intake, it is easy to induce vitamin D deficiency rickets, resulting in increased neural excitability, which may lead to frequent waking at night and crying, accompanied by sweating, occipital baldness and other symptoms. One year old baby waking up frequently crying at night, may also be caused by other reasons, if the symptoms of frequent recurrence, or accompanied by other obvious discomfort, should be as early as possible to consult a doctor, diagnose the cause, give targeted treatment.