A patch of hairlessness in the middle of the head can be diagnosed as androgenetic alopecia or baldness. Androgenetic alopecia can occur in both men and women, and used to be called seborrheic alopecia because of the seborrhea. This type of alopecia is distinguished from other causes of alopecia, such as malnutrition, drug-related alopecia, endocrine disorders, and anemia. The sudden onset of male pattern baldness in women, especially when accompanied by acne, hirsutism, menopause, etc., should be considered an endocrine disorder. If it is baldness, then the cause of its onset is still not completely clear, but it is currently believed to be related to excessive mental stress and physical exertion, in addition to having a certain degree of heredity.