In the clinic, the causes of occasional failure of men are divided into physiological factors and pathological factors. First of all, if the life pressure is too big, the emotion is under tension for a long time, it will make the body in sub-healthy state, the body functions decline, it will also have an impact on the sexual function, and the occasional failure to perform. If ever in the psychological frustration or past too much sex life experience, leading to a serious decline in desire, will also appear occasionally do not lift, or the body is in a state of fatigue for a long time, leading to a decline in the indicators lead to poor sexual function. Pathological factors many diseases can cause the occurrence of not lifting, such as high blood pressure, thyroid function abnormalities, high blood sugar, high blood fat, and penile cavernous arteriovenous fistula, penile vascular sclerosis, etc., if men with low testosterone will also appear in this phenomenon, need to consult a doctor in a timely manner, to avoid delaying the treatment.