RESUMO
The basic objective of urodynamics is to reproduce the patient's symptoms while evaluating the lower urinary tract directly, with objective quantification of parameters, correlating the symptoms with the findings of the test. Traditionally, it is used: a) to diagnose lower urinary tract dysfunction, quantify its severity and determine the most significant abnormality, b) to predict the consequences of lower urinary tract dysfunction on the upper urinary tract, c) to predict the results of therapeutic interventions and possible complications and d) to investigate the causes of treatment failures. In this article we will refer to the indications of urodynamics taking into account the recommendations of the main international urological societies: 1) in women with urinary incontinence, with emphasis on those who have stress urinary incontinence and who will undergo surgery, 2) in men with non-neurogenic lower urinary tract symptoms suggestive of benign prostatic hyperplasia, and 3) in patients with neurologic involvement of the lower urinary tract ("neurogenic bladder"), considering the classification of neurological disorders according to the risk over the upper urinary tract. (AU)