Full-term babies have been crying, generally a normal physiological phenomenon, but we can not rule out some diseases, such as intestinal cramps, vitamin D deficiency rickets, etc., such as the annoyance is serious and accompanied by other symptoms should be promptly consult a doctor to find out the cause of the disease. 1. Physiological factors: due to the baby’s young age, easy to be frightened, can be manifested as restless sleep, crying all the time. It may also be that the baby wears thicker or tighter clothing, sweating too much, causing discomfort, thus always crying. 2. Pathologic factors: (1) intestinal spasm: intestinal spasm is caused by paroxysmal strong contraction of the smooth muscle of the intestinal wall, mostly occurring in infants and young children. When full-term infants have an attack of intestinal spasm, it mainly manifests itself as paroxysmal crying and difficult to appease, and sometimes there can be facial flushing, abdominal distension and so on. (2) Vitamin D deficiency rickets: due to the lack of vitamin D in the body, resulting in calcium and phosphorus metabolism malfunction, increased neural excitability, which can cause night terrors, irritability, irritability and other symptoms, thus appearing to cry all the time. Full-month baby has been crying, after excluding physiological factors, should be timely consultation, improve the relevant examination, if necessary, by the doctor for targeted treatment, so as not to delay the condition.