Cystitis in women is usually caused by infection at catheterization. The very great improvement in the asepsis of this procedure that has taken place in recent years has in a corresponding degree diminished the frequency of cystitis. Infection at catheterization is caused not only by the use of a dirty catheter, but by the conveyance of septic material from the external genitals or the urethra into the bladder. For this reason the nurse or the physician should never pass the catheter by touch, as was sometimes formerly taught. The parts should be exposed to view, and the external genitals, vestibule, and meatus should be cleansed. Cystitis may also be caused by extension of urethritis; by inflammation of adjacent organs; by abnormal urine; by constitutional diseases, as the exanthemata; by injuries to the bladder and displacement of this organ; and by retention of urine. _Symptoms._--The symptoms of cystitis vary with the stage and the character of the affection. Pain, frequent urination, and tenesmus are usually present. In the acute stages there may be an elevation of temperature. There is a feeling of fulness in the bladder, with pain in the region of this organ. The pain is increased by motion and by the erect position, which increases the intra-vesical pressure. The pain is constant, and is not relieved by evacuation of the bladder. Pressure upon the base of the bladder through the vagina causes pain. This is a useful diagnostic point. There is a frequent desire to urinate, and the passage of urine is followed by straining efforts or tenesmus. The alteration in the character of the urine has already been mentioned. In time the general system suffers from secondary renal disease and from absorption, through the bladder, of the ingredients of decomposed urine and septic material from the mucous membrane. The _diagnosis_ of cystitis is easily made by proper examination. It should always be remembered that not every woman who complains of painful and frequent urination and vesical tenesmus is necessarily suffering with cystitis. These symptoms are often caused by disease of the urethra, by displacement of the uterus, which drags upon the neck of the bladder, by the pressure of a tumor, or by displacement of the bladder such as may follow laceration of the perineum. Women may often be seen who have been treated for weeks for cystitis without avail, and who are immediately relieved of all symptoms by the replacement of a retroverted uterus or the closure of a torn perineum. These conditions may in time result in cystitis, but the disease usually disappears with the cure of the causative lesion.