It is necessary to state whether correlations between objective findings and subjective perception of symptoms exist, and whether the patient's 'everyday' symptoms are reproduced during objective studies, when the results are reported. The principle aim of urodynamics is to reproduce a patient's symptoms and to provide a patho physiological explanation for them. The purposes of this study is to evaluate whether there is a relation between the position (sitting/standing up vs supine position) and the bladder sensations in both healthy volunteers and patients with OAB. Furthermore we would like to study patient perception of bladder condition and bladder filling and volumes voided as well as the functional and maximal bladder capacity in patients with OAB.