Acute cystitis is mostly caused by bacterial infection, the main reasons are: 1, bladder intrinsic factors: such as the presence of foreign bodies, stones, tumors and other bladder dysfunction easily triggered; 2, personal factors: such as drinking, late at night, fatigue, improper sex life, resistance to decline easily caused by infections; 3, physiological factors: women’s urethral orifices are 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 injuries caused by dysfunctions of urinary drainage resulting in bacterial growth to induce infection.