The appearance of black hair in the pores of the back, generally considered to be a simple hair follicle mouth inside the hair, usually a normal phenomenon, no need to worry. However, the situation may also be caused by disease factors, should be observed and promptly seek medical attention. It is common in adolescents during the puberty development period, due to the unstable level of androgen as well as estrogen and progesterone regulation and metabolism in the body, it is easy to see that the sweat hair inside the pores of the back grows vigorously. If the site is limited, simply appear local hair follicles appear black hair, consider that it may be due to long-term external use of glucocorticoid creams caused by thickening, pigmented changes, it is recommended to choose the external use of calcium-regulated neurophosphatase inhibitors to alleviate the symptoms. In addition, female patients with excessive androgen secretion can also appear and are considered to be suffering from polycystic ovary syndrome. This condition requires the patient to go to the hospital for sex hormone six laboratory tests and ultrasound examinations to further clarify the diagnosis, and after the diagnosis is confirmed, medication or surgical treatment can be chosen under the guidance of the doctor. After finding black hairs in the pores of the back, it is important to carefully observe whether other symptoms such as infection appear, and if acne, itching, redness or other uncomfortable reactions appear, it is recommended to go to the hospital in time.