Androgenetic baldness is a disease characterized by a progressive reduction of hair on the top of the head. It is called male pattern baldness in men and female pattern baldness in women, and they are not the same. 1. Male pattern baldness: The onset of the disease usually begins at puberty, with the hair gradually becoming thinner, softer, thinner and easier to fall out. Most of the hair loss starts from the sideburns on both sides of the forehead, gradually extending in an “M” shape toward the top of the head, while the forehead hairline gradually recedes. In some patients, hair loss and thinning begins at the top of the head, while in others, hair loss occurs simultaneously at the frontal sideburns and the top of the head. After several years to decades of development, in severe cases, the hair on the top of the head can even be completely lost, the local skin is smooth, the pores shrink, forming a “bald”, while the occipital and both sides of the temporal “half circle” still have residual normal hair, known as This is called “Mediterranean haircut”. Zhou Cheng, Department of Dermatology and Venereology, Peking University People’s Hospital Male pattern baldness is usually accompanied by premature hair loss, seborrhea, greasy scalp and increased dandruff, but other parts of the body such as the beard and armpit hair are generally unaffected. 2. Female pattern baldness: The symptoms are generally lighter than those of male pattern baldness, with diffuse hair loss, manifested as thinning hair on the top of the head, usually without complete loss of hair, and the hairline on the forehead does not move back. Female patients with androgenetic alopecia usually have female pattern baldness, but a small percentage of male patients can also have female pattern baldness.