Symptoms usually appear after the age of 50. The size of prostate enlargement is not directly proportional to the symptoms, which are determined by the degree of obstruction, the speed of development of the lesion, and whether it is combined with infections and stones, and the symptoms may be mild or severe, but there are no symptoms when the enlargement does not cause obstruction or when it is mildly obstructed, and there is no obvious effect on health. Prostatic hyperplasia manifests itself clinically in two groups of symptoms, namely, bladder irritation and obstruction. Bladder irritation symptoms Prostate irritation symptoms include frequent urination, urinary urgency, increased nocturia, and urge incontinence. These symptoms of prostatic hyperplasia are symptoms of irritation and obstruction caused by the complex interactions between the prostate and the bladder. Prostatic hyperplasia is an increase in urethral resistance, and the bladder needs to overcome its resistance to expel urine, which increases the pressure on the detrusor muscle, resulting in compensatory hypertrophy of the smooth muscle of the bladder wall, and although the detrusor muscle can maintain the relatively normal expulsion of urine, its function is not completely normal. Bladder irritation symptoms may be related to bladder outlet obstruction, non-obstructive detrusor instability. And the production of provocative symptoms: urinary frequency and urgency. Frequent urination is the earliest clinical symptom in patients with prostatic hyperplasia. Normal men urinate once every 3~5h, the bladder capacity is 300~500ml. the elderly prostate hyperplasia urinary frequency is due to the loss of compensation of the forced urethra muscle, the bladder can not be completely emptied, the amount of residual urine increases, the effective capacity of the bladder is thus reduced, so that the time of urination is shortened, first of all the frequency of nocturnal urination increases, each time the amount of urine is not much; followed by daytime urinary frequency, the frequency of nocturnal urination increases, due to the forced urethra muscle instability or the kidneys Loss of the normal rhythm of urine production at night caused by the vagus nerve excitation at night, bladder tone is reduced, resulting in increased residual urine volume, may also be the cause of increased urination, 50% to 80% of patients still have urinary urgency or urgency incontinence. If accompanied by bladder stones, or infection, urinary frequency and urgency are more obvious, and accompanied by urinary pain. 2, obstruction symptoms The prostate continues to enlarge the urethra resistance increases, bladder outlet obstruction, when the bladder is difficult to compensate, there will be waiting for urine, thin urine line, and weakness, urinary effort, intermittent urine flow, terminal dribbling, prolonged urination time, incomplete emptying, urinary retention and even overflow incontinence, the above are prostate enlargement obstruction symptoms. Due to prostatic hyperplasia compression of the urethra, urethral resistance increases, the bladder detrusor muscle must be over-contracted in order to begin to maintain urination, and the patient may experience delayed micturition, weakness, a short ejaculation, a thin urinary line, and prolonged voiding time. If the obstruction is further aggravated, the patient must add abdominal pressure to maintain urination. With the decrease of abdominal pressure, there is an interruption of urine flow such as dribbling after urination, and bladder residual urine occurs when the bladder forced urethral muscle is not compensated; when the amount of residual urine in the bladder is increased, resulting in over distension of the bladder, and when the pressure is increased, overflow incontinence can occur. When sleeping at night, the pelvic floor muscles are relaxed, urine is more likely to overflow on its own, and nocturnal incontinence occurs. Sympathetic nerve excitation in the body so that the prostate gland contraction and tension increases, so some patients usually residual urine is not much, but in the cold, drinking, holding urine or other reasons cause sympathetic nerve excitation, acute urinary retention can also occur. 3, other clinical symptoms (1) hematuria: over 60 years old men with prostatic hyperplasia part can appear different degrees of hematuria, usually for the onset of the beginning or end of hematuria. The cause of hematuria for the prostate mucosa on the capillary congestion and small blood vessels dilated and by the hyperplasia gland pull, when the bladder contraction, so that the dilated blood vessels rupture caused by hematuria. Occasionally, there is a large amount of bleeding, and the blood clot may fill the bladder and require emergency treatment. (2) urinary tract infection symptoms: prostate hyperplasia congestion, obstruction is very easy to cause urinary tract infection, the occurrence of cystitis, there can be urinary pain, urinary urgency, urinary frequency, dysuria and other symptoms of aggravation. Obstruction aggravated by urinary retention caused by upper urinary tract fluid, ureteral reflux can be secondary to upper urinary tract infection, fever, back pain, systemic toxicity symptoms, renal function will be further impaired; some patients do not have symptoms of urinary tract infection, but a large number of leukocytes or pus cells in the urine can be detected in the urine culture can be a bacterial growth, so in the case of prostate hyperplasia, whether conservative treatment or surgical treatment, and at the same time need to active anti-inflammatory treatment. (3) stones: prostate hyperplasia leads to lower urinary tract obstruction, especially in the emergence of residual urine, crystalline particles in the urine, leukocytes, shedding cells or small stones in the upper urinary tract is discharged into the bladder, prolonged stagnation time in the bladder, become the core of the formation of stones, prostate hyperplasia combined with the incidence of bladder stones can be more than 10%, bladder stones can cause perineal pain, severe pain during urination, sudden interruption of the urinary stream, easy to lead to infection, accelerate the growth of stones, often with light or heavy hematuria. (4)Symptoms of incomplete compensation of the forced urethra muscle: some patients with prostatic hyperplasia, with the further aggravation of obstruction, develop extensive structural and functional damage to the bladder wall, most of the forced urethra muscle is replaced by extracellular matrix, and some patients with bladder diverticulum, which aggravates the incomplete emptying of the bladder, at this time, the worsening of symptoms of dyspareunia is mainly due to the incompetence of the forced urethra muscle rather than because of the anatomical obstruction. (5) Acute urinary retention: that is, the inability to urinate on its own, manifested by a sudden distension of the bladder resulting in severe pain. Sometimes a small amount of urine in one place intermittently, i.e., filling incontinence. Acute urinary retention does not mean that the incomplete compensation of the forced urethra muscle has developed to the end stage, and a well-compensated bladder can also be induced by the use of alpha-adrenergic drugs, prostate infections, and over distension of the bladder. Indwelling catheterization may restore bladder function. (6) Renal function impairment: prostatic hyperplasia causes upper urinary tract obstruction, episodic hydronephrosis and renal insufficiency, a small number of patients suffering from prostatic hyperplasia, there are no clinical symptoms, only found during routine physical examination, or when the doctor complains of loss of appetite, anemia, elevated blood pressure, or lethargy, slowness of consciousness, etc., and then only found to be prostatic hyperplasia caused by obstructive hydronephrosis, renal function impairment after examination. The symptoms of prostatic hyperplasia are only found to be obstructive hydronephrosis and renal impairment. Therefore, if older men have unexplained symptoms of renal insufficiency, the possibility of prostatic hyperplasia symptoms should be ruled out first. (7) Other: Because prostatic hyperplasia can cause increased urethral resistance, long-term urination difficulties lead to increased abdominal pressure, inguinal hernia, prolapse or internal hemorrhoids can occur, masking the symptoms of prostatic hyperplasia, and resulting in diagnostic and therapeutic errors.