4. Facts & Figures
PVD is classified as a pain syndrome and often coincides with other pain syndromes like fibromyalgia and the irritable bowel syndrome (IBS). This kind of syndrome classifications lack a clear nosological definition and taxonomy. In every day practice therefore a pragmatic solution is chosen. Leading scientist and/or therapists formulate some kind of working definitions and accessory taxonomy, preferably based on consensus. This provisionary categorization inevitably leads to some variations in terms of facts and figures. Based on the work of Weijmar Schultz et al (2012, 2013) we will focus here on the more formal definition, classification (taxonomy) and prevalence of PVD.