Spinal cord injury is a relatively common disorder. There are many causes of spinal cord injury, including congenital injury, inflammation, tumors, tuberculosis, and trauma. Spinal cord injuries can occur in the cervical, thoracic, lumbar and sacral medulla. If there is a complete loss of sensation and movement in the body below the level of injury, it is called a complete spinal cord injury, also known as paraplegia. If the body retains some function below the level of injury, the spinal cord injury is incomplete. Damage to the cervical segment is tetraplegia, damage to the thoracic segment is spastic paralysis of both lower extremities, damage to the lumbar segment is characterized by paralysis of both lower extremities, and damage to the sacral cone often results in complete destruction of penile erection and ejaculatory function. Paraplegia is a transection of the spinal cord and the nerves passing through the spinal canal, which can lead to disruption of the continuity and integrity of nerve fibers up to the brain and down to the motor organs, which is tantamount to cutting the communication links between the command and the subordinate units, thus causing three symptoms, namely, impairment of random motor, sensory and vegetative control. Paraplegia is mostly seen in young people, with an average age of about 30 years. The impact of spinal cord injury on the sexual function of male patients is most severe, with 70% to 80% of adult patients with spinal cord injury no longer able to have sexual intercourse, while the corresponding female patients have less change in sexual function and little change in fertility. Male sexual activity can be divided into the following four phases according to neurophysiological processes: penile erection; semen discharge (transit in the epigonial glands); ejaculation (which is the most intense self-centered sensation); and orgasm. Among these, ejaculation will involve the parasympathetic nerves from segments 2 to 4 of the cervical medulla and the sympathetic nerves from segments 11 to 12 of the thoracic medulla (inferior ventral nerve), along with the somatic nerves from segments 2 to 4 of the sacral medulla (pudendal nerve). The level of injury determines its effect on male sexual function, but it is not reliable to determine the extent and symptoms of spinal cord injury solely at the level of the spine. Examination of sacral medullary function is important. Examination of sensory sensitivity often reveals some residual sacral medullary function; this finding is relevant for further classification. Examination of casual anal sphincter and levator muscle tension provides information on casual motor capacity at the level of the sacral medulla. Examination of the superficial anal reflex, bulbocavernosus reflex, and levator reflex can provide information on sacral reflex capacity. The Achilles reflex reflects the somatic reflexes of sacral 2 to 4. Urodynamic examination will also provide important information about the sacral medulla. With the help of neurological function tests, random motor activity and sensation at the level of the sacral medulla may determine the clinical type of neurogenic impotence, the classification of which depends on the presence or absence of reflex activity in sacral 2 to 4. The presence of activity indicates the presence of reflex activity, which means that upper motor neuron sexual reflex activity is still present; when there is a lack of activity, it is called absence of reflex activity, which means that lower motor neuron sexual activity is lost. About 90% of patients with cervical medullary injury have the ability to have an erection, and 70% of them have an erection that is sufficient for sexual intercourse, but they only have a reflex erection produced by stimulating the genitals. Reflex erections are accomplished through a reflex arc between the genitalia and the sacral medulla. They have a lack of sensation in the penis, scrotum and perineal tissues, and a lack of random motor control of the pelvic muscle groups. However, these patients can maintain an erection through constant stimulation by a partner or by themselves, such as stimulating the genitals, anus, pulling on pubic hair, or rubbing the thighs. In addition, reflex erections can be produced when the patient receives stimulation from within the body to the rectum, bladder, etc. However, in patients with cervical medullary injury, there is no brain-controlled psychological erection (e.g., during sexual fantasies), because it is regulated by the thoracolumbar erectile center. Ejaculation rarely occurs in those with complete cervical medullary injury, and successful ejaculation occurs in only 1-5% of cases, but the ability to ejaculate is preserved in approximately 25% of patients with incomplete injury. Thoracic marrow injury results in similar outcomes to cervical marrow injury. The major difference between the two is that those with thoracic marrow injuries will have more skin surface available as a source of sexual pleasure than those with cervical marrow injuries. When spinal cord injury occurs in lumbar 2 to sacral 1, both psychogenic and reflex erections are present, but the two cannot be coordinated and ejaculatory orgasm through genital stimulation is impossible! Sexual function is more affected when the sacral medulla is injured. Since both the erectile and ejaculatory centers of the penis are located in these segments, sacral medulla injury can cause impotence and inability to ejaculate. Stimulation of the genitalia of these patients cannot cause reflex erection, while 25% to 60% of patients can still develop psychogenic erection, probably because the signals of psychogenic stimulation from the brain are transmitted to the penis through the uninjured thoracolumbar segment of the vegetative nervous system. The skin and muscles of patients with cervical or high thoracic marrow injury are not controlled by the higher centers, and the slightest stimulation will cause “tonic contraction” and even headache, slowed heart rate, and even sympathetic irritation such as lethal increase in blood pressure. Sexual activity can induce autonomic hyperreflexia syndrome, which can be relieved by stopping sexual intercourse. Emptying the bowels beforehand and taking drugs such as Tibericin or Mecamylamine can help prevent this phenomenon. Patients and partners should pay sufficient attention to this potential danger and should handle it appropriately by adopting appropriate sexual positions to prevent it from happening. How a patient with a spinal cord injury prepares for sexual activity is key to sexual life. Patients may become incontinent during sexual activity. Patients can regularly empty their bladder by applying pressure and natural drainage. In addition, patients should develop regular bowel habits and empty any stool that cannot be passed on their own in a timely manner. Most men with spinal cord injury cannot have children, and the fertility rate for men with all types of spinal cord injury is 1-10%, with only 1-5% for those with complete spinal cord injury. The main cause of infertility is twofold, many patients simply cannot get an erection and ejaculate, and the quality of semen is reduced. The situations described above are artificial generalizations, and it is impossible for everyone to be exactly right, and there are bound to be some complex exceptions. In particular, the determination of complete transection versus partial injury is sometimes difficult. Judgment of sexual function can only be made after the condition has been completely stabilized.