The first basic knowledge I. Definition Benign prostatic hyperplasia (BPH) is the most common benign disease among the causes of dysuria in middle-aged and elderly men. BPH is mainly characterized by histological hyperplasia of the interstitial and glandular components of the prostate, anatomical enlargement of the prostate (benignprostaticenlargement, BPE), lower urinary tract symptoms (lowerurinarytractsymptoms, LUTS), and urodynamic obstruction of the bladder outlet (bladderoutletobstruction, BPH). bladderoutletobstruction, BOO). II.Epidemiology Histologically the prevalence of BPH increases with age, initially usually occurring after the age of 40 years, greater than 50% by the age of 60 years, and as high as 83% by the age of 80 years. Similar to the histologic presentation, symptoms such as dysuria increase with age. Approximately 50% of men with histologic diagnosis of BPH have moderate to severe lower urinary tract symptoms. Some studies have shown that it appears that Asians are more likely to have moderate-to-severe BPH-related symptoms than Americans. Third, the etiology of BPH must have the two important conditions of aging and functional testes. Domestic scholars investigated 26 Qing Dynasty eunuchs, found that 21 people’s prostate has been completely inaccessible, or obvious atrophy. However, the specific mechanism of the occurrence of BPH is not clear, and may be caused by the balanced disruption of proliferation and apoptosis of epithelial and mesenchymal cells. Associated factors are: androgens and their interaction with estrogen, prostate mesenchymal a gland epithelial cell interaction, growth factors, inflammatory cells, neurotransmitters and genetic factors. Fourth, pathology McNeal divided the prostate into peripheral zone, central zone, migratory zone and periurethral glandular zone. All BPH nodules occur in the migratory zone and periurethral glandular zone. Early nodules in the periurethral glandular zone had an exclusively interstitial component; whereas early migratory zone nodules showed predominantly hyperplasia of glandular tissue with a relative decrease in the amount of interstitium. Smooth muscle in the interstitial tissue is also an important component of the prostate, and these smooth muscles, as well as the periurethral tissues of the prostate, are innervated by adrenergic, cholinergic, or other enzyme transmitter nerves, with the adrenergic nerves playing a major role. There is an abundance of G receptors, especially αl receptors, in the prostate and bladder neck, and activation of such adrenergic receptors can significantly increase prostatic urethral resistance. The anatomical envelope of the prostate is closely related to lower urinary tract symptoms, and due to the presence of this envelope, the hyperplastic gland is pressurized and bulges out toward the urethra and bladder thereby exacerbating urethral obstruction. After prostate hyperplasia, the hyperplastic nodule compresses the rest of the gland to form a “surgical envelope”, which is clearly demarcated from the rest of the gland. After surgical removal of the hyperplasia, the compressed gland remains, so the prostate gland can still be detected by postoperative rectal palpation and imaging. Pathophysiological changes Prostatic hyperplasia leads to prolongation of the posterior urethra, deformation of pressure, narrowing and increase in urethral resistance, causing high bladder pressure and related urinary symptoms. With the increase of bladder pressure, compensatory hypertrophy of bladder forced urethral muscle occurs, and the forced urethral muscle is unstable and causes the related symptoms of urinary storage phase. If the obstruction is not relieved for a prolonged period of time, the urethra loses its compensatory capacity. Upper urinary tract changes secondary to BPH, such as hydronephrosis and renal impairment, are mainly due to urinary retention due to bladder hypertension and ureteral reflux. Clinical manifestations, diagnosis and treatment The main clinical manifestations of BPH include bladder irritation, obstruction and related comorbidities. Symptoms may appear sequentially or develop progressively throughout the course of the disease. Diagnosis of BPH is based on symptoms, physical examination, especially rectal examination, imaging, urodynamic examination and endoscopy, etc. The treatment of BPH mainly includes observation and waiting, medication, minimally invasive treatment and surgical treatment. The purpose of treatment is to improve the quality of life of patients and protect renal function at the same time. The choice of treatment should be based on the severity of the patient’s symptoms, the combination of auxiliary tests, local medical conditions and patient compliance. Diagnosis of BPH Male patients over 50 years of age who present to the doctor with lower urinary tract symptoms should first consider the possibility of BPH. In order to make a definitive diagnosis, the following clinical evaluation is required. I. Initial assessment 1. History questioning (recommended) (1) Characteristics and duration of lower urinary tract symptoms and their accompanying symptoms (2) History of surgery and trauma, especially pelvic surgery or trauma (3) Past history and sexually transmitted diseases, diabetes mellitus, and neurological disorders (4) History of medications, which will help to find out if the patient is currently or has recently taken any medications that interfere with the function of the bladder outlet (5) Patient’s general condition (6) International Prostate Symptom Score (LPSS) The I-PSS scale is now internationally recognized as the best means of determining the severity of symptoms in patients with BPH.The I-PSS score is a subjective reflection of the severity of lower urinary tract symptoms in patients with BPH, which has no significant correlation with the maximum urinary flow rate, the amount of residual urine, or the volume of the prostate. I-PSS score patients are categorized as follows: (Total score 0-35) Mild symptoms 0-7 points Moderate symptoms 8-19 points Severe symptoms 20-35 points (7) Quality of life score (QOL) QOL score (0-6 points) is to understand the patient’s subjective feelings about the level of their current lower urinary tract symptoms along with his/her life, and it is mainly concerned with the extent to which BPH patients are bothered by their lower urinary symptoms and whether they are able to tolerate them. Its main concern is the degree to which BPH patients are bothered by their lower urinary tract symptoms and whether they can tolerate them, hence it is also known as the botherofscore. Although the above two scores cannot completely summarize the impact of lower urinary tract symptoms on the quality of life of BPH patients, they provide a platform for communication between doctors and patients and enable doctors to understand the disease status of patients. 2, physical examination (recommended) (1) rectal examination (digitalrectalexamination, DRE) lower urinary tract symptoms in patients with rectal examination is very important, need to be carried out after bladder emptying. Can know whether there is prostate cancer: foreign scholars clinical research has confirmed that the rectal diagnosis of patients suspected of having abnormalities in the final diagnosis of prostate cancer in 26-34%. And its positive rate with the increase of age is on the rise. It can understand the size, shape, texture, the presence of nodules and tenderness of the prostate, whether the central sulcus has become shallow or disappeared, as well as the anal sphincter tone. Rectal palpation is not precise enough to determine the volume of the prostate, and transabdominal ultrasound or transrectal ultrasound can now more accurately describe the morphology and volume of the prostate. (2) Local neurological examination (including motor and sensory). 3.Urine routine (recommended) Urine routine can determine whether patients with lower urinary tract symptoms have hematuria, proteinuria, pyuria and urine sugar. 4.Serum PSA (recommended) Prostate cancer, BPH, and prostatitis may elevate serum PSA. Therefore, serum PSA is not unique to prostate cancer. In addition, urinary tract infections, prostate puncture, acute urinary retention, indwelling catheterization, rectal palpation and prostate massage can also affect serum PSA values. Serum PSA is closely related to age and race. Serum PSA generally rises after the age of 40, and PSA levels vary among different races. Serum PSA values correlate with prostate volume, but the correlation between serum PSA and BPH is 0.30 ng/ml and with prostate cancer is 3.5 ng/m1 [6]. Serum PSA can be used as an indication for puncture biopsy of prostate cancer. Generally, PSA ≥4ng/m1 is used as a cut-off point in clinical practice. As a risk factor, serum PSA can predict the clinical progression of BPH, thus guiding the choice of treatment. 5.Ultrasound(Recommended) Ultrasound can understand the shape and size of the prostate, the presence or absence of abnormal echoes, the degree of protrusion into the bladder, and the amount of residual urine. Transrectal ultrasonography (TRUS) can also accurately determine the volume of the prostate (the formula is 0.52 × anterior-posterior diameter × left-right diameter × upper and lower diameter). In addition, transabdominal ultrasonography can understand the urinary system (kidneys, ureters) with or without fluid, dilatation, stones or space-occupying lesions. 6, urine flow rate examination (recommended) urine flow rate has two main indicators (parameters): maximum urine flow rate (Qmax) and average urine flow rate (averageflowrate, Qave), of which the maximum urine flow rate is more important. However, a decreased maximal flow rate cannot distinguish between obstruction and hypocontractility of the urethra. A combination of other tests and, if necessary, urodynamics is required. Maximum urinary flow rate is highly variable and volume-dependent, so it is more accurate to perform the test when the urine volume is 150-200 ml, and the test can be repeated if necessary. According to the results of the initial evaluation, some patients need further examination 1, Voiding diary (optional) Voiding diary is valuable in patients with lower urinary tract symptoms, such as predominantly nocturia, and the recording of a 24-hour voiding diary can help to identify nocturnal polyuria and excessive water intake [1-2]. 2, Blood creatinine (optional) Bladder outlet obstruction due to BPH can cause renal impairment and elevated blood creatinine. However, recent data from the MTOPS study suggests that blood creatinine testing may not be necessary if voiding is normal, because renal impairment due to BPH has many other changes already in place before reaching elevated blood creatinine, such as hydronephrosis, dilated ureteral reflux, etc., which can be definitively determined by ultrasonography and intravenous pyelography. It is only recommended to choose this test when the above lesions have occurred and renal insufficiency is suspected. 3.Intravenous urography (IVU) examination (optional) If patients with lower urinary tract symptoms are accompanied by recurrent urinary tract infections, microscopic or microscopic hematuria, suspected hydronephrosis or ureteral dilatation reflux, and urinary stones, they should undergo intravenous pyelography. It should be noted that intravenous urography is prohibited when the patient is allergic to contrast media or has renal insufficiency. If necessary, isotope nephrography should be used instead of intravenous urography to check the renal function and the drainage of upper urinary tract. 4.Urethrography(Optional) This test is recommended when urethral stricture is suspected. 5. Urodynamics (optional) This test analyzes the function of the urethra muscle and determines the presence of bladder outlet obstruction by means of the pressure-flow rate function graph and A-G graph. It is recommended when there is doubt about the cause of bladder outlet obstruction or when bladder function needs to be evaluated, in combination with other related tests to exclude neurologic lesions or neurogenic bladder due to diabetes mellitus. 6. Urethrocystoscopy (optional) This test is recommended when there is a suspicion of urethral stenosis or intravesical space-occupying lesions in patients with BPH. Through urethrocystoscopy, the following can be known: (1) the characteristics of urethral or bladder neck obstruction due to prostate enlargement; (2) obstruction due to elevation of the posterior lip of the bladder neck; (3) the formation of bladder trabeculae and diverticula; (4) bladder stones; (5) determination of the amount of residual urine; (6) bladder tumors; (7) the location and degree of urethral stricture. Computerized tomography (CT) and magnetic resonance imaging (MRI) are not recommended due to the high cost of these tests. Fourth, the initial evaluation of BPH patients summary 1, recommended tests ① history and I-PSS, QOL score ② physical examination (rectal examination) ③ routine urinalysis ④ serum PSA ⑤ ultrasonography (including the measurement of residual urine volume) ⑥ urinary flow rate 2, optional tests ① diary of urination ② urodynamics ③ intravenous urography ④ urethrogram ⑤ urethral cystoscopy 3, recommended tests ① computerized body scanning ② magnetic resonance imaging (MRI) due to the high cost of the examination is generally not recommended. Body scan ②Magnetic resonance imaging