The different ways of barh and ablution are basic processes in both popular and professional medicine. The two basic tasks of medicine are prevention and curing. Although under the notion of „medicine" people usually mean only curing. Approaching medicine from the washing customs it is clear that both prevention and curing have equal importance. The author first describes the notions of clean and unclean, then she shortly sums up the mythological and magical symbolics of the different qualities of water from curing and prevention point of view. Finally ahe sketches the system of bath and ablution treatments used in curing and preventing. Practically this system is rearranging of the washing customs which is suitable for classifying the different fields of washing from the aspect of medicine.