More and more people are convinced to be afflicted with diseases caused by ill-defined environmental factors. Until now it has also not been possible to delineate unambiguously common features to describe a syndrome-like pattern which is the essential requirement for rational prophylactic and therapeutic intervention. Despite of this scientific status a wide variety of supposedly diagnostic and therapeutic methods of unproven efficacy is currently advertised and often applied in a polypragmatic manner. Besides providing a description of the different techniques their clinical relevance is critically evaluated.