Children can not sleep may be caused by lifestyle habits, or functional dyspepsia, hyperthyroidism and other diseases. 1. lifestyle habits: if the child has too much time to sleep during the day, or watch TV and play cell phones before going to bed, etc. may disrupt the normal work and rest, and then cause insomnia, is a normal physiological phenomenon. 2. Functional dyspepsia: The occurrence of this disease is related to high sensitivity of internal organs, excessive gastric acid, heredity, Helicobacter pylori infection, and poor dietary habits. Children will have typical symptoms such as abdominal pain and bloating, but some of them will also have mental problems such as sleeplessness and anxiety. 3. Hyperthyroidism: It may be caused by thyroid nodules, thyroid tumors and other diseases. The child will have a hyper appetite, sleeplessness, irritability and other symptoms. If the child can not sleep to rule out the physiological phenomenon, you need to go to the hospital in time to improve the examination, to clarify the cause of the disease.