The causes of severe hair loss in children may be caused by genetic factors, malnutrition, excessive stress, and pathogenic infections. 1. Genetic factors: androgenetic alopecia is the most common, especially in male children. 2. Malnutrition: If a child is a picky eater, and the nutrients in the body are not enough, the scalp follicles may not be able to take in enough nutrients, which may cause the child to suffer from severe hair loss. 3. Excessive stress: like the child’s hair loss is serious, but also may be usually too much mental stress or sudden stress related, which in turn causes baldness and other symptoms. 4. Pathogenic infections: Some children may suffer from staphylococcus aureus infection, trichophyton infection, etc., which destroys the scalp follicles, thus causing the symptoms of severe hair loss. There may also be other causes of severe hair loss in children, which need to be further clarified with the doctor, and then targeted treatment and therapy.