Hair thinning on both sides of the girl may be due to lack of iron, mental factors, bad habits and other reasons. 1. Lack of iron: malnutrition, blood loss and other factors may lead to a lack of iron in the body, the lack of iron will lead to the occurrence of iron-deficiency anemia, resulting in insufficient blood supply to the head, which is prone to hair follicle function is impaired, affecting the normal growth of hair and hair on the temples of the hair thinning. 2. Mental factors: long-term mental tension, sudden mental stimulation and other factors, may lead to endocrine and hormonal changes, resulting in hair loss, and the symptoms of hair thinning. 3. Bad habits: frequent late nights, alcoholism, frequent perming and dyeing of the hair and other factors, may lead to hair follicle atrophy, lose the ability to produce hair, and the two sides of the hair gradually thinning symptoms. Women’s hair on both sides of the thinning may also be caused by other factors, it is recommended that patients seek medical attention in a timely manner, under the guidance of the doctor for relevant examinations, clear causes and follow the doctor’s instructions for symptomatic treatment.