Functional impotence tends to be more sudden in onset and shorter in duration. Sexual desire is generally no obvious change, but the penis is poorly erected during sexual arousal, or can be erected, but the desire to coitus is immediately atrophy. The initial disease is mostly caused by the bad place, time, accidental factors during sexual intercourse, and the disharmony between the two parties involved in sexual intercourse. Later, every similar place and time of sexual intercourse, or even the same partner, or in the process of sexual intercourse on the previous failure of the process of memory, or have some scruples, will produce impotence phenomenon. In solitude, self-excitement, normal sleep at night, the penis can be satisfied with the erection, but once the memory of the process of failure, or lack of confidence in the continuation of sexual intercourse, the penis will be soft. Sometimes the penis can be erected well when facing different partners and satisfactory sexual intercourse can be obtained. In addition, it is often accompanied by mental and psychological symptoms, such as anxiety, sadness, depression, and dysphoria. Some patients may have premature ejaculation, spermatorrhea, or non-ejaculation during sexual intercourse.