The purposes of testing urethral function are to identify pathophysiological conditions and to grade the severity of the condition. Urethral pressure measurements are the cornerstone in the urethral function tests and have been performed for a century. The urethral closure pressure can be calculated if the bladder pressure is measured simultaneously with the urethral pressure. The techniques have different characteristics that are important to acknowledge to minimize artefacts. The bladder pressure and the urethral pressure are measured simultaneously with one sensor in the bladder and one or more sensors in the urethra during the filling urethro-cystometry. Acoustic reflectometry is the most recently developed technique for simultaneous measurements of pressure and cross-sectional area. The systems are based on the micro-tip transducer techniques. The catheters have several sensors in the axial length of the catheter and each sensor has 8–16 circumferential pressure sensing foci.