Simply put, this test can be done as long as the patient has urinary abnormalities such as dyspareunia, urinary frequency, urinary incontinence, etc., and no urinary tract infection. In some cases, patients who have been urinating frequently for a long time but do not urinate much each time and have no abnormal findings on clinical examination are likely to be troubled by the instability of the detrusor muscle, that is, the spontaneous contraction of the detrusor muscle of the bladder when they are not urinating. The diagnosis can be confirmed by urodynamic bladder manometry. Then again, prostatic hyperplasia is a common cause of dyspareunia, which usually manifests as low urinary flow rate, but low urinary flow rate does not necessarily mean bladder outlet obstruction, and normal or very good urinary flow rate cannot exclude bladder outlet obstruction, because the urinary flow rate is influenced by many factors, such as contraction of the detrusor muscle, which has to be effective, complete sphincter diastole, and unobstructed opening of the urethra. Therefore, whether the bladder outlet is obstructed by the enlarged prostate gland or due to impaired contraction of the bladder forceps is difficult to diagnose by general clinical examination alone, but a combined urodynamic pressure-flow rate measurement can make a definitive diagnosis. If it is determined that the bladder outlet is obstructed while the contraction of the forceps is normal, invasive treatment such as surgery is likely to have the best outcome. Urodynamic examination of patients with BPH has two main aspects: 1) the presence of bladder outlet obstruction, for which only pressure-flow rate analysis can provide an accurate answer with respect to current technology; 2) the function of the bladder forcing muscles, including bladder storage function, such as bladder compliance , stability, bladder sensation and bladder capacity, and also the emptying function of the bladder, mainly to understand the contraction force of the forceps.