Hydrotherapy is the use of water in the treatment of disease. Hydrothermal therapy additionally uses its temperature effects, as in hot baths, saunas, wraps, etc. Water therapy has been around for centuries. The ancient Greeks took therapeutic baths.
Water is an important ingredient in the traditional Chinese and Native American healing systems.
A Bavarian monk, Father Sebastian Kneipp helped re-popularize the therapeutic use of water in the 19th century. There are now many dozens of methods of applying hydrotherapy, including baths, saunas, douches, wraps, and packs. It exploits the body's reaction to hot and cold stimuli, to the protracted application of heat, to pressure exerted by the water and to the sensation it gives. The nerves carry impulses felt at the skin deeper into the body, where they are instrumental in stimulating the immune system, influencing the production of stress hormones, invigorating the circulation and digestion, encouraging blood flow, and lessening pain sensitivity. Generally, heat quiets and soothes the body, slowing down the activity of internal organs.