Section I. Bacterial cystitis I. Acute bacterial cystitis: Etiology: The high incidence of cystitis includes four groups: school-age girls, women of childbearing age, men with prostate enlargement, and the elderly. Cystitis is caused by a variety of factors: ① intrinsic bladder factors such as stones, foreign bodies, tumors and indwelling catheters, which destroy the defenses of the bladder mucosa and cause bacteria to adhere to the bladder wall; ② urinary obstruction at the neck of the bladder, which causes urinary obstruction and loss of urinary flushing; ③ neurological damage, such as neurological disorders that damage the nerves innervating the bladder, causing difficulty in urination and causing infection. The pathway of bladder infection is most common upstream, with a higher incidence in women than in men, because the female urethra is short and often contaminated by the contents of the adjacent vagina and anus, i.e. the fecal-perineal-urinary tract infection pathway. In contrast, male circumcision, prostatitis, and vesiculitis can also cause cystitis. Infections of the lower stars are cystitis secondary to kidney infections. Bladder infections can also be caused by lymphatic spread of infection from neighboring organs, but are less common clinically. Cystitis caused by gram-negative bacilli is the most common, accounting for more than 70% of cases. Clinical symptoms: Acute cystitis can occur suddenly or slowly, with burning pain in the urethra during urination, pain mostly occurring during interruption of urination, pain in the perineum or pubic bone, and also radiating to the femur and lumbosacral area. If there is also urinary retention, the pain is persistent and distended or frequent, often accompanied by urinary urgency, and when the frequency is severe, it is similar to urinary incontinence. The acute cystitis in female patients occurs mostly after a new marriage, the course of acute cystitis is short, such as timely treatment, the symptoms are more in about 1 week. Second, chronic bacterial cystitis Chronic cystitis is a chronic inflammatory disease of the bladder wall caused by a non-specific infection with mainly gram-negative bacilli (such as Escherichia coli). It is more frequent in women and can develop at all ages, especially in middle-aged and elderly people. Etiology: common causes are urethral strictures, bladder neck obstruction, urinary bladder stones, foreign bodies, tumors and genital infections, etc. In women, it can be caused by urethral orifice obstruction, vestibular gland abscess, and also because acute cystitis is not treated thoroughly in time or re-infection occurs several times and transforms into chronic cystitis, and mostly combined with other diseases. Clinical symptoms: The symptoms of chronic cystitis are generally similar to those of acute cystitis, with irritating symptoms such as urinary frequency, urgency, increased nocturia and bladder or pelvic pain predominating, but to a lesser extent, usually without obvious signs or with non-specific signs. Carnal hematuria is rare. It is characterized by persistent and recurrent signs of bladder irritation, cloudy urine, and a long duration of disease.