I. Definition and Epidemiology Erectile dysfunction (ED) is the persistent inability of the penis to achieve and maintain an erection sufficient for satisfactory sexual intercourse over the past 3 months; ED is one of the most common sexual dysfunctions in men. Although ED is not a life-threatening disease, it is closely related to the patient’s quality of life, sexual partner relationships, family stability, and is an early warning sign of many physical diseases. Second, the ED risk factors (a) age Current research suggests that: age is the strongest independent factor in ED-related risk factors. It is generally believed that as age increases, serum androgen levels decrease significantly may be the direct cause. However, there are no findings that demonstrate a significant relationship between a decrease in serum free testosterone and ED. In addition, as age increases, the structure of the penile white membrane and cavernous body changes, which may lead to a decrease in the ability to block venous blood return; the increased prevalence of cardiovascular diseases, hypertension and diabetes, as well as the treatment of these diseases, all impair the erectile function of the penis to varying degrees, and this trend also increases with age. (B) somatic diseases 1, cardiovascular diseases Cardiovascular diseases are the main somatic diseases associated with ED, including atherosclerosis, peripheral vascular disease, hypertension and myocardial infarction. Cardiovascular disease causes arterial ED by affecting the blood supply to the cavernous arteries. 2, diabetes mellitus can affect erectile function by affecting the autonomic nervous system, peripheral vascular system and the mental nervous system. The severity and prevalence of ED is significantly related to the age and duration of diabetes, type of diabetes, glycemic control, diabetic neuropathy, diabetic nephropathy and hypertension. 3, abnormal lipid metabolism The role of hypercholesterolemia in sexual dysfunction is controversial. 4, chronic prostatitis Some patients with chronic prostatitis have symptoms such as premature ejaculation, decreased libido, erectile dysfunction and painful ejaculation. The mechanism of chronic prostatitis leading to sexual dysfunction is unknown, most scholars believe that anxiety, depression, low self-esteem, loss of energy, fatigue, paranoia and insomnia are its main causes. The recurrence and non-healing of long-term testicular distension, perineal and penile discomfort, and lower urinary tract symptoms also add to the psychological burden of the patient as most chronic prostatitis patients’ sexual dysfunction is due to psychological factors, and in addition to medication, more psychological counseling and treatment is needed. 5, chronic liver and kidney insufficiency The prevalence of ED in patients with alcoholic cirrhosis is 70%, while in patients with non-alcoholic cirrhosis is 25%, suggesting that the prevalence of ED is related to liver insufficiency. The prevalence of ED in patients with chronic renal insufficiency is as high as 45%, but the pathophysiological mechanisms are unknown. Another study pointed out that for kidney transplant recipients, if the transplanted kidney function is normal, most patients can regain the level of sexual function before the disease. (iii) drugs Some anti-hypertensive drugs play an important role in the occurrence of ED, and ED associated with drugs for the treatment of heart disease accounts for about 28% of reports; other drugs, such as hypoglycemic drugs and antidepressants can also lead to ED. Cardiac active drugs: long-term use of cardiac glycosides can lead to ED, along with gynecomastia feminization and hypoactive libido, the mechanism is unknown, but the serum levels of estrogen, luteinizing The mechanism is unknown, but elevated serum levels of estrogen, decreased levels of luteinizing hormone (LH) and testosterone may play a role. In recent years, digoxin has been found to cause ED by inhibiting the action of sodium/potassium ATPase. Hormones: Estrogens and luteinizing hormone releasing hormone (LHRH) analogs used in the treatment of prostate cancer often cause ED. exogenous estrogens inhibit gonadotropin releasing hormone secretion and decrease testosterone levels in the blood. The application of LHRH analogs can also reduce libido in 92% of patients and ED in 86% of patients. Psychotropic drugs: Most drugs that can produce central nervous system sedation or depression can lead to ED. causes may include elevated serum prolactin, sedative effects, anticholinergic effects, reduced activity of the dopamine system and the central effect on the limbic system, etc. (D) habits and ED-related habits include: long-term smoking, alcohol and drug use, etc. 1, smoking Epidemiological investigation that smoking can lead to ED, some people believe that smoking can increase the likelihood of ED. The MMAS study showed that the baseline level of smoking in moderate or severe ED was two times that of controls (24% vs. 14%). In patients being treated for heart disease, the age-corrected prevalence of complete ED was 56% in smokers versus 21% in nonsmokers; in patients being treated for hypertension, the prevalence of complete ED was significantly higher in smokers than in nonsmokers (20% vs. 8.5%); in addition, smoking may exacerbate the effects of medications on ED. 2, alcohol abuse In a survey of sexual function in 50 patients admitted for alcohol abuse, the prevalence of ED was 54% in alcoholics compared with 28% in controls compared with the general population after age and social relationship matching (P < 0.05). In another study evaluating sexual dysfunction in male and female alcoholics, 63% of male alcoholics had sexual dysfunction, mainly erectile and libido disorders, compared with 10% of controls after age-matching. (E) Life status Divorced, living alone or ? Johannes concluded that educational attainment had a positive effect on erectile function. After age correction, the prevalence of ED was lower in those with college or higher education than in those with high school or less. Ansong believes that the above phenomenon may be due to the low education level and low income people are often accompanied by a lack of attention to health, as well as poor living conditions, while smoking and alcohol abuse tend to be higher. (vi) Trauma and medical factors ED is associated with pelvic surgery, especially radical prostatectomy, cystectomy, and rectal surgery. In radical prostatectomy, the use of a nerve-preserving procedure can significantly improve postoperative erectile function, but more than 50% of patients still need to seek other forms of postoperative treatment to improve their erectile function; patients with symptoms of lower urinary tract obstruction are also associated with a higher prevalence of ED; genital, pelvic, and spinal cord injuries can destroy the nerves and blood vessels distributed in the penis, which is also a risk factor for ED; spinal cord The severity of ED due to spinal cord injury is determined by the segment of the injury, the presence of spinal shock and the degree of trauma, and the prevalence of ED in people with spinal cord injury is 64% to 94%. The incidence of ED is higher in patients with prostate cancer treated with radiation therapy than in patients undergoing radical prostatectomy with preservation of nerves.