Why is my 12 year old losing his hair?

Possible Causes of Hair Loss in Children

For children, typical reasons for hair loss may include fungal or bacterial infections, telogen effluvium (stress-induced hair loss), and traction alopecia. Nevertheless, the leading cause of hair loss among children is scalp ringworm, a treatable fungal infection. Most hair loss conditions can be effectively managed by doctors, and many cases are reversible.