Insufficient congestion of glans after erection is mainly caused by narrowing of penile blood vessels, which may be caused by sympathetic nervous tension, penile arterial atherosclerosis, congenital penile arterial stenosis and other reasons. 1. Sympathetic nervous tension: due to excessive sympathetic nervous tension, resulting in penile blood supply artery contraction, penile vascular constriction stenosis, which leads to a decrease in penile cavernous blood supply, the emergence of insufficient congestion of the glans after erection. 2. Penile atherosclerosis: due to hypertension, high blood pressure, high blood fat and other diseases, resulting in narrowing of the penile blood supply arteries, resulting in insufficient blood supply to the penile corpus cavernosum, resulting in insufficient congestion of the glans after erection. 3. Congenital stenosis of penile artery: due to congenital stenosis of penile blood supply artery, the penile corpus cavernosum can not be expanded and filled with blood, resulting in insufficient blood supply to the penis and insufficient congestion of glans after erection. In addition, it is recommended that patients go to the hospital emergency room in time, and follow the doctor’s instructions for treatment to avoid delaying the condition.