Hydrotherapy is most easily defined as the therapeutic use of water. It has been around for centuries and is probably the oldest of all therapies. It was once thought to treat everything from typhoid to tumors, and even general well-being in Roman and Turkish bathe. Today it is relied on as an aid in treating muscular and joint injuries, arthritis, and it is still treating general well-being in modern saunas and private bathtubs.
Underwater massage is the most effective and widely used of the pressure-movements treatments. The water is circulated out of the bath, returning as a powerful jet, which can be directed to any part of the body. Since the body is nearly weightless in water and the muscles are relaxed, a more intense massage is possible, and it is important to lie down and rest for about 15 minutes afterwards.

Whirlpool baths, with their gently swirling currents, are a standard part of physiotherapy for injuries to joints and connective tissue, and for nervous conditions.
Aerated water, which occurs naturally in certain mineral springs but which can also be produced artificially, is a less powerful but still very effective form of underwater massage. It is used in physiotherapy and is a general tonic.
Other treatments:
Packs and cloth compresses soaked in hot water (to dilate the blood vessels) or cold water( to relieve congestion and swellings) can be applied to large or small areas.
Mineral water is often drunk for the reputed healing qualities of its mineral content. Sulfur and nitrogen, for example, are thought to help relieve rheumatism. Use bottles mineral waters during fasting- itself is a purifying process.
Steam inhalation is used to treat mucous membrane inflammation and to relieve impaired breathing and wheezing caused by colds, asthma, or other respiratory disorders.