Men do not get hard in coitus refers to erectile dysfunction, which may be caused by lesions, psychological factors, surgery and other reasons. 1. lesions: normal vascular function is the basis of physiological penile erection, when the penile blood vessels have arteriosclerosis, venous leakage and other lesions, erectile dysfunction will also occur. 2. Psychological factors: such as daily disharmony between husband and wife, asymmetry or lack of sexual knowledge, bad sexual experience, etc., patients may experience depression, anxiety and other phenomena, which can affect the erectile function and erectile dysfunction. 3. Surgery: It may be caused by the doctor’s improper operation during the surgery to injure the cavernous body of the penis, have to remove the cavernous body of the penis and other reasons. Mainly because the penis needs the cavernous body of the penis to be filled with blood in order to be erected, so patients can develop erectile dysfunction. It is recommended that patients with erectile dysfunction go to the hospital in time and follow the doctor’s instructions for treatment to avoid delays.