A 5-year-old boy often falls down, the cause may be motor nerve dysplasia, lack of calcium and so on. 1. Motor Nerve Dysplasia: When a child has motor nerve dysplasia, it may lead to poor stability during exercise and easy to fall. 2. Calcium deficiency: Children are in a period of growth and development, if the intake of calcium is not enough to meet the growth needs of the body, it will lead to abnormal bone development. At this time, you can go to the hospital to check the calcium element, you can also do X-ray examination, in order to determine whether the bone development is normal. There may be other reasons for a 5-year-old boy’s frequent falls, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.