The causes of hair loss in children generally include malnutrition, baldness and heredity. 1. Malnutrition: When a child suffers from malnutrition and lacks minerals and proteins in the body, it may cause a lack of nutrients needed for hair growth, which will lead to hair loss and thinning hair. 2. Patch baldness: hair loss may also be related to patch baldness, there are one or more rounded areas of hair loss on the head, and this condition is usually patch baldness. 3. Heredity: If the parents have thinning hair, the child may also have more hair loss and thinning hair. There may be other reasons for hair loss in children, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then treat under the guidance of the doctor.