Acute cystitis is mostly caused by bacterial infection, the main reasons are: 1, bladder intrinsic factors: such as the presence of foreign bodies, stones, tumours and other bladder dysfunction easily triggered; 2, personal factors: such as alcohol, late at night, fatigue, inappropriate sex life, resistance to decline easily caused by infection; 3, physiological factors: women’s urethral orifice is short, close to the anus and vagina, easy to infected with bacteria; 4, indirect infections: such as peripheral inflammation in the pelvic cavity, prostatitis, urethral gland infection caused by an indirect infection of the bladder; 5, neurological injury: neurological injuries, lumbosacral nerve injury caused by dysfunction of urinary tract resulting in bacterial growth to trigger infection.