Erectile dysfunction, abbreviated as ED in English, is defined as the persistent (for at least 6 months) inability of the penis to achieve and maintain a sufficient erection for satisfactory sexual intercourse. It can be classified as mild, moderate or severe by degree. Generally speaking, erectile dysfunction is divided into three categories: 1. Psychological erectile dysfunction is often caused by problems such as psychological or mental factors, without somatic lesions. It includes external factors and internal factors. External factors are poor sexual environment, couple relationship, poor female cooperation, sexual stimulation is not enough, depression and pressure from work, family and other aspects; internal factors are my fear of sexual intercourse, worry, anxiety and bad feelings about sex. 2, organic erectile dysfunction including endocrine, neurological, vascular and other pathologies, so can be divided into endocrine, neurological, vascular erectile dysfunction. There are not many erectile dysfunctions that really belong to this category. 3, mixed erectile dysfunction refers to the existence of both functional and organic erectile dysfunction, usually occurs on the basis of organic erectile dysfunction, feel that they can not do anything about sexual intercourse, so the pressure on the mind, resulting in functional erectile dysfunction.