ABSTRACT
Urodynamic studies play an important role in the evaluation and diagnosis of lower urinary tract dysfunction. Evaluation can be undertaken in a noninvasive manner, with a voiding diary, a pad test, and free flow rate or in an invasive manner by cystometry, pressure flow assessment, and urethral pressure profiling. The normality of urodynamic parameters in a healthy population is found in ranges rather than in precise values. To objectively measure subjective complaints of lower urinary tract symptoms, patients are asked to complete a voiding diary. B. T. Haylen et al. constructed the Liverpool nomograms based on the maximum and average flow rates of nor mal volunteers. During the filling phase, abdominal and bladder pressures are recorded via rectal and urethral catheters, respectively, whereas detrusor pressure is calculated by subtracting abdominal pressure from bladder pressure.
