Lower urinary tract dysfunction produces a huge burden on sufferers in particular and on society in general. Lower urinary tract symptoms have a high prevalence in the community: 5% of children aged 10 wet the bed,while 15% of women and 7% of men have troublesome incontinence; and in elderly men of 75,benign prostatic hyperplasia occurs in more than 80% of indivi- als,with benign prostatic enlargement coexisting in up to half this group and half of these having bladder outlet obstruction. The confusion felt in many people’s minds as to the role of urodynamics has receded for the most part. The need to support the clinical assessment with objective measurement has become accepted by most clinicians speci- ising in the care of patients with lower urinary tract symptoms (LUTS). Since the ?rst edition of this book in 1983, urodynamics has become more widely accepted. In the last 20 years the number of urodynamic units in Britain and Europe has increased rapidly and almost every hospital of any signi?cance embraces urodynamic investigations as an essential part of the diagnostic armamentarium of the urology and gynaecology departments. Further, specialists in geriatrics,paediatrics and neurology recognise the importance of urodynamics in the investigation of a signi?cant minority of their patients. Despite the technological innovations that have seen the introduction of computerised urodynamics, the development of neuro-physiological testing and the introduction of new techniques such as ambulatory monitoring, the objectives of this book remain unchanged.