The penis is always not too hard to consider for erectile dysfunction, is due to premature ejaculation, impotence or kidney deficiency, penile cavernous arteriovenous fistula and penile arterial stenosis and other reasons. Penile arterial stenosis of blood supply to the cavernous body will decline in stimulation of the glans insufficient congestion, the penis is not easy to erect a long time in a weak state. For the existence of kidney deficiency patients often external manifestations of physical exhaustion and weakness, kidney function will decline will directly affect the penile erection. Penile cavernous arteriovenous fistula is a direct traffic between the penile arteries and veins, seriously affecting the penile congestion patients are not easy to have an erection, hard. Usually mental stress, regular late night fatigue will affect the body’s metabolism, each organ will also appear corresponding decline, including renal failure, so that impotence, premature ejaculation phenomenon. The above situations will lead to penile weakness, not easy to harden, the specific situation is recommended to the regular hospital through the examination to further determine.