If the penis goes limp once it is inside, there is no problem if intercourse can be completed normally after re-stimulation, which may be caused by excessive tension. If the penis can not be erected afterward, or the degree of erection is not enough to complete sexual intercourse for more than 3 months, then it indicates impotence. Occasionally appear once in a couple of life in the soft, or again after the stimulation can normally complete sexual intercourse is not a problem, may be caused by excessive tension, the patient needs to adjust the state of mind, timely communication with their spouses, relaxation, elimination of fear, the situation will be improved. Impotence is male erectile dysfunction, refers to men who can not consistently obtain or maintain sufficient penile erection to complete a satisfactory sex life for more than 3 months. The causes of impotence are psychological and organic. Psychological causes include discordant relationship between husband and wife, lack of sexual knowledge, bad sexual experience, and excessive stress. Organic causes include vascular causes such as atherosclerosis, arterial injury, arterial stenosis, etc.; neurological causes such as stroke, Parkinson’s disease, spinal cord lesions, lumbar disc herniation, etc.; structural abnormalities of the penis itself and inflammation. Treatment mainly includes lifestyle improvement, treatment of primary underlying diseases, psychological counseling and medication. Medications include sildenafil and other drugs, which should be applied under the guidance of a doctor. If the patient has any discomfort, he should consult the doctor in time for examination and early treatment.