There are many reasons for girls to have hairy legs, such as physiological factors, polycystic ovary syndrome, hormonal side effects and so on. 1. Physiological factors: some girls with hairy legs may be due to genetic factors, or androgen levels are more intense secretion and other factors, the phenomenon is physiological. 2. Polycystic ovary syndrome: women with polycystic ovary syndrome will cause metabolic disorders, excessive secretion of androgens in the body, which can lead to hairy legs, menstrual disorders, obesity, infertility and other phenomena. 3. Hormone side effects: If the skin of the legs for a long time using glucocorticoid drugs, can also lead to local hairy phenomenon. The cause of girls leg hairy for many reasons, if exclude physiological factors, it is recommended to go to the hospital in time to improve the examination, a clear diagnosis, to give targeted treatment.