The cause of spot baldness is not completely clear, and spot baldness in 15-year-old boys may be related to genetic factors, mental stress, stress reaction, endocrine factors, immune system diseases and so on. 1. Genetic factors: if parents have baldness, the possibility of 15-year-old boys having baldness will increase, which is related to heredity. 2. Mental stress: there is a possibility of excessive academic burden at this age, which leads to mental stress, etc., thus inducing the phenomenon of spot baldness. 3. Stress reaction: family changes, violent mood swings or trauma and other stress reactions may also cause baldness in 15-year-old boys. 4. Endocrine factors: when a 15-year-old boy enters puberty, the hormone secretion in his body is unstable, or the endocrine disorders caused by irregular life and diet may induce spot baldness. 5. Immune system diseases: if the patient suffers from autoimmune diseases, it may also induce spot baldness in 15-year-old boys. The cause of baldness is not yet clear, 15-year-old boy baldness may have other reasons, it is recommended that patients go to the regular hospital in time for examination, to clarify the cause of the disease and follow the doctor’s instructions for treatment.