A reasons of cystitis are..

Bacterias as bowel stick, streptococcus, staphylococcus, protei, viruses trichomonads, chlamidase, yeast fungus,tuberculosis infections,were micro organism penetrates through urea canal, or with blood current from other organs. And after flu, angina, arvd, nidus any,and if pyelonephritis courses on the active form, uterine inflamed,ducts,defloration after,were microbes enter in urea bladder on lymph current.

When microflora vagina damaged,thus cystitis is urologic and gynecologic problem.
Cystitis beginning developing  if breaching blood circulation in wall urea and pelvis, poor urinary,poor immunity after fatigue,stress,depression. over a cooling, poor move of life, eating spicy and salted meal more, poor menu,and hygienic for sex organs as failure too.
If urinary bladder washing with hot water, if damaging by endoscopy, catheter, or foreign body,allergy inflamed of a urinary bladder, and attacking of immune complex,delay urea in bladder, over cooling.
Acute cystitis display within two days,and in a week symptoms will to disappear.
A males having if phimosis,adenoma, stones in urea bladder, strictures, cancer prostate,as second cystitis,as a complication of other damage,and process is chronic and long.
Chronic cystitis is inflamed a process in kidneys, and bacterias entering in ducts having with pus process.