Hydrotherapy (Greek ύδρο-, idro-, "water-", from ancient Greek ὕδωρ, hýdor, "water" and θεραπία, therapía, "therapy"), also hydropathy and German hydrotherapy, is the methodical application of water for the therapeutic treatment of acute or chronic discomfort, to stabilize body functions (hardening), to prevent, to rehabilitate and / or to regenerate. Above all, the temperature stimulus of the water is used, less the pressure or the buoyancy as a therapeutic stimulus.
Water is used in all three states of aggregation: ice, cold / tempered / warm water and steam.