The effects of hydrotherapy on various systems of the human body are the result of stimuli such as temperature, mechanics, and chemistry.
The skin is rich in blood vessels and nerve endings. Therefore, the expansion or contraction of the blood vessels of the skin can have a great influence on the distribution of blood in the body, such as 1/3 of the blood of the whole body when the skin telangiectasia is expanded. The nerves on the skin have a large number of nerve endings of the spinal nerves and vegetative nerves. The stimulation of the peripheral nerves can affect the function of the central nervous system and internal organs, and achieve anti-inflammatory, antipyretic, analgesic, sedative, hypnotic, excitatory, sweating, diuretic and muscle-reducing. Ligament tension, relieve convulsions, promote metabolism, improve nervous system regulation and other purposes.