Hydrotherapy uses water, both internally and externally, for health purposes. It includes treatments like saunas, steam baths, and contrast therapy that use the physical properties of water like specific heat, thermal conductivity, buoyancy, resistance, and hydrostatic pressure. Physiologically, hydrotherapy can cleanse wounds, strengthen muscles, improve cardiovascular function, and induce relaxation. It is used for conditions like wound care, pain control, and edema management. Proper application of hydrotherapy involves evaluation, treatment selection, explanation to the patient, application of treatment, outcome assessment, and documentation. Different hydrotherapy treatments include water jets, underwater massage, mineral baths, whirlpools, and hot or cold baths