A 7-year-old girl’s hair loss is very serious, which may be caused by physiological reasons, or by pathological reasons (such as androgenetic alopecia, tinea capitis and seborrheic dermatitis). 1. Physiological reasons: if the child usually sleeps poorly, mental stress, there will be physiological hair loss. 2. Pathological causes (1) Androgenetic alopecia: it can be caused by hereditary factors, or by exuberant secretion of androgen. (2) Tinea capitis: caused by fungal infection, besides hair loss, it can also manifest as itching and scaling. (3) Seborrheic dermatitis: for patients with seborrheic dermatitis, due to local skin irritation and inflammation, severe cases may cause damage to the hair, leading to hair loss. If a 7-year-old girl has abnormal hair loss, it is recommended to go to the hospital in time to identify the specific cause and treatment.