Normally, the bladder has a capacity of about 400 ml. For many patients, such as those with tuberculosis of the bladder, resulting in bladder contracture, the bladder capacity will be significantly reduced in this case. For patients with prostatic hyperplasia, the bladder capacity will gradually increase because of bladder outlet obstruction, mainly because of poor urination, resulting in increased residual urine, a large amount of urine in the bladder that cannot be urinated, a chronic dilated bladder condition, and during periods of inflammation, the bladder mucosa is congested and edematous and cannot effectively fill with urine, resulting in a significant decrease in bladder capacity. Under normal circumstances, a decrease or increase in bladder capacity is an abnormal phenomenon and should be noted.