Modern medicine believes that impotence is related to functional and organic factors: 1. Functional factors Mainly mental and psychological factors. Commonly there are the following aspects: ① Psychosexual development is affected: the attitude towards sex is accumulated from various aspects such as cultural background, family influence, personal experience and spouse’s sexual response. The influence of religious beliefs, parental concepts, sex-related books and glimpses of sexual events also constitute a variety of sexual experiences: such as negative family attitudes toward sexual issues; inappropriate cultivation of sexual identity in early childhood; reprimanded for fondling genitals; lack of proper understanding of sexual life; little knowledge of sex; first failed sexual intercourse, psychological trauma, etc. ② Emotional abnormalities: such as inferiority complex, lack of self-confidence; fear of sex, worrying about the inappropriate size of the penis; fear of sexual failure, pregnancy and contracting sexually transmitted diseases; mental depression or mania, etc. ③ disharmony between spouses: spouses do not trust each other, suspect that the wife is having an affair, both parties quarrel due to family conflicts, the wife lacks attraction to the husband, the wife suffers from gynecological disease or urinary tract infection refuses to have intercourse, etc., resulting in disharmony between spouses. The relationship between spouses is not close, not harmonious, and even mutual disgust, which will inevitably lead to an abnormal sexual life, sexual activities on both sides or one party to the other party does not closely cooperate, so that the integrity of sexual life is damaged, so that sexual intercourse can not be carried out smoothly. The male partner may not get the proper stimulation due to the female partner’s lack of cooperation or aversion, and may also suffer from impotence due to apprehension about sex. According to statistics from the Edinburgh Sexual Dysfunction Clinic, 47% of men believe that the cause of sexual disorders is disharmony in their daily relationships, while 68% of their spouses also believe that it is caused by disharmony in their daily relationships. The response process of normal sexual activity cannot be completed. ④ Inappropriate or inadequate sexual stimulation: Adequate and appropriate sexual stimulation for an individual means that he gets various kinds of enjoyment such as visuals, hallucinations, fantasies, as well as consciousness and emotions. The type of stimulation an individual requires may be related to the way a former lover made love or masturbation habits. Some adult men require direct and intense touching of the penis to stimulate an erection, while the average person can achieve the same effect by relying on thoughts or fantasies. Some people are accustomed to prolonged masturbation, or have frequent sex, so that the nervous system is often in a state of overexcitement and eventually exhaustion. ⑤ neurasthenia: prolonged illness, excessive fatigue, causing neurasthenia. ⑥ Influence of inhibitory factors: Research has found that psychological factors causing impotence also include stress, anxiety and depression factors, such as work, family, economic pressure and secondary emotions. Under work, social and family stress, many people experience physical and emotional symptoms. Susceptibility to stress and individual differences determine the severity of their symptoms, and when attempts are made to improve these symptoms, new stresses may be added. Anxiety and depression may be a reaction to non-sexual causes or a product of sexual perceptions, and are generally considered to be major factors in psychosexual dysfunction. Anxiety can arise from beliefs, cognitive environment, and the impact on sexual function is often related to fear of being able to initiate and maintain an erection. Fear of disease, pregnancy, intimacy, and ejaculation have been shown to be common inhibiting causes. Other causes include aversion to a spouse or other women, shame formed by education at an early age, and guilt about otherwise normal sexual behavior. (7) Other factors: such as premature ejaculation, non-ejaculation during sexual intercourse, long-term absence of orgasm, medical influence, doctors arbitrarily diagnosed as impotence disease, and reveal to the patient the emotion that it is difficult to cure, so that the burden of thought is increased and lose confidence in treatment. The above-mentioned factors make the cortical inhibition of sexual excitement strengthen and the excitability of the medullary erectile center diminish, thus impotence occurs. 2, organic factors (1) endocrine ① diabetes mellitus: cause parasympathetic neuropathy of the innervated perineum, etc. (2) Hypothalamus and pituitary abnormalities: tumors are the most common, and others include infiltration of peripheral lesions and pituitary blood flow disorders. These lesions contribute to a decrease in gonadotropin release, leading to impotence; they can also lead to an increase in prolactin due to a decrease in dopamine, which in turn becomes impotent. (③) Primary sexual insufficiency: there are two types: congenital and acquired. Congenital conditions such as Klinefelter syndrome and other chromosomal defects, congenital bilateral orchidism, acquired conditions such as mumps, concomitant orchitis, vascular disorders, radiotherapy and chemotherapy can cause impotence due to reduced free testosterone and increased LH and FSH in the blood. Cortisolism: Increased cortisol can inhibit the secretion of testosterone by gonadotropins and testicular interstitial cells, resulting in a decrease in the absolute value of testosterone, which in turn can lead to impotence, which occurs in about 70% of patients with this disease. ⑤ Hyperthyroidism: 71% of male patients with hyperthyroidism have hypoactive sexual desire and 56% have impotence. However, impotence is not parallel to the degree of hyperthyroidism. In patients with hyperthyroidism with impotence, T3, T4, LH, total testosterone, testosterone binding protein and 17β-estradiol are increased, while FSH and free testosterone may be normal. After chorionic gonadotropin injection in hyperthyroid patients, androgen aromatization is accelerated and androstenedione and testosterone are converted to estrone and estradiol, respectively. Therefore, increased estrogen may be the main cause of impotence. (6) Hypothyroidism: Patients have decreased testosterone and testosterone binding protein and increased prolactin. The occurrence of impotence is related to degenerative changes of testicular varicocele and decreased interstitial cells due to systemic protein synthesis disorder. (7) Adrenal insufficiency: The cause of impotence due to this lesion is less clear. It may be related to a decrease in LH secretion from the pituitary gland and testosterone secretion from the testicular interstitial cells due to wasting and malnutrition. (8) Feminizing tumors: Feminizing tumors can occur in the adrenal glands or testicular mesenchymal cells, causing gynecomastia and testicular atrophy. ⑨ Hyperprolactinemia: Increased prolactin can occur for many reasons, such as taking drugs that block dopamine receptors or reduce dopamine reserve, excessive estrogen, hypothyroidism, chronic renal failure and hemodialysis, and pituitary tumors. The diagnosis can be made on the basis of plasma PRL values. 80% to 90% of patients with increased PRL values have hypoactive libido and impotence, mostly accompanied by a decrease in testosterone and a decrease in LH. This may be due to the inhibitory effect of increased PRL on the hypothalamus, which in turn decreases GnRH secretion and reduces LH secretion from the pituitary gland. However, sometimes testosterone is normal, so sexual dysfunction may be due to the direct action of PRL on the central nervous system, which inhibits -5-reductase and changes inert testosterone to active dihydrotestosterone. (2) Neurological ① Multiple sclerosis: It is characterized by an episodic course and can be accompanied by impotence during the attacks, so it is often difficult to diagnose correctly and easily misdiagnosed as psychogenic impotence in the early stage. Almost all patients with advanced disease have changes in sexual function, often accompanied by delayed ejaculation, non-ejaculation and loss of libido. ② Chronic alcoholism: about 10% of patients with chronic alcoholism have polyneuropathy, which leads to impotence. (③) Lumbar disc herniation: In general, impotence does not occur frequently with lumbar disc herniation and laminectomy, but it is thought that impotence can occur with disc herniation at L4-5 and with sacral nerve root damage. (3) Vascular ① Inadequate arterial blood supply: mainly due to atherosclerosis. It mostly occurs in the main-iliac artery or the internal pubic artery, but also in the dorsal penile artery or the deep penile artery. The lesions include intimal hyperplasia, middle layer fibrosis, calcification, and luminal narrowing, thus causing vasoembolic lesions, often associated with age and diabetes mellitus. Arterial hypoplasia can also lead to inadequate arterial blood supply and impotence. ② Venous drainage disorders: often due to excessive venous drainage of the cavernous body, resulting in the inability to maintain an erection. Such as congenital or medical fistula between the corpus cavernosum and glans, venous malformation of the white membrane, etc. (3) Arteriovenous fistula: mostly seen in arteriovenous fistulae of the internal vessels of the pubic area, which prevent the cavernous sinus from filling. (4) Trauma and surgical trauma Impotence can also be triggered after surgery such as traumatic brain injury, vertebral fracture, paraplegia, traumatic testicular atrophy, prostatic hyperplasia removal, abdominal aortic aneurysm removal, bilateral kidney transplantation, etc. (5) Genital lesions ① Congenital malformations: congenital penile curvature, bipenis, micropenis, penile scrotal displacement, retroversion of bladder, urethral epispadias and hypospadias, etc., can lead to inability to get an erection due to malformation, curvature, cavernous body dysfunction, and also psychological impotence due to psychological effects. ② Penile injury: penile traumatic dissection or cancerous excision, which makes the penis absent or partially absent, can produce impotence. Therefore, one-stage anastomosis should be strived for after penile dissection, and local radiotherapy can be used for small penile cancer to try to maintain sexual function. Blunt injury to the erect penis can sometimes cause severe angulation or erectile dysfunction after healing. (3) Secondary penile deformity: The severity of fibrous cavernous lesions varies. Small fibrous plaques may not affect function, while more severe ones may cause pain and different degrees of penile curvature or deformity and affect erection. Regardless of the method of treatment for abnormal penile erection, impotence still occurs in more than 50% of cases. The reason for this is the formation of scars in the cavernous body after prolonged erection, which can also be secondary to various bypass surgeries. (6) Drug sex There are many commonly used drugs that can have a strong inhibitory effect on sexual function in clinical practice. Therefore, when examining patients with sexual dysfunction, the focus should be on understanding the effects of the drugs in question. The effect of drugs on sexual function, generally have the following conditions: such as the use of antipsychotic drugs, a large number of sedative drugs, can make the serum prolactin rise and cause erectile dysfunction; the use of antihypertensive drugs, due to reduce the sympathetic action and other mechanisms to affect penile erection, the use of estrogen, anti-androgen drugs, inhibit the sexual center’s ability to respond to sexual stimulation; the use of anticholinergic drugs, reduce parasympathetic action. (7) Age factors According to statistics the incidence of impotence in men is 5% at the age of 40 and reaches 15% by the age of 70. Plasma testosterone levels decrease with age, and an increase in obstructive vascular lesions may be a cause. In addition, the stimulus needed to produce a reflex erection is the sense of touch in the penis, and the acuity of touch is significantly reduced in the elderly, which can also cause impotence. (8) Internal diseases Any acute or chronic disease can affect sexual performance, but the pathway through which the effect occurs and the extent of the effect is often unpredictable, and the mechanism can be either direct action on the sexual organs and tissues or through the influence of consciousness. Usually cardiopulmonary diseases do not cause impotence, unless they are severe, extremely weak or have fear after myocardial infarction to affect libido and sexual function. Impotence often occurs in patients with chronic renal failure, mostly due to the effects of uremia, testicular atrophy and decreased testosterone levels, nervous system dysfunction, and decreased serum zinc levels. Treatment with dialysis and kidney transplantation may improve, but cannot restore to the pre-disease level.