In a narrow sense, spa refers to beauty care in SPA, with various forms, such as cold bath, hot bath, alternating hot and cold bath, seawater bath, hot spring bath and tap water bath. Every bath can relax tense muscles and nerves to a certain extent, eliminate toxins in the body and prevent diseases. In recent years, it has been found that massage with various aromatic essential oils in spa can accelerate fat burning and have slimming effect. The specific heat and heat capacity of water in spa are very large, and it is easy to carry heat energy. There are two ways of heat transfer in spa: conduction and convection. Besides heat transfer, water also has mechanical functions, such as buoyancy, pressure and the impact of water flow and water jet. Water can dissolve various substances and drugs, and these solutes can also play a therapeutic role. Spa can be used alone or in combination. Spa nursing is simple and easy, unlike drug therapy, which has many side effects, and unlike mineral spring therapy, which is limited by the place, environment and conditions of recuperation. Spa nursing has many effects, mainly including: constant temperature cooling, muscle relaxation, brain cell regeneration and resurrection, increasing blood oxygen, promoting heart function, promoting blood circulation, skin bleaching, cleaning pores, removing body odor, removing aging cuticle of skin and so on. Her principle is that through the alternate use of various hydrotherapy equipment, oxygen-rich water is absorbed and acupoints are massaged by hydrotherapy, so as to achieve the functions of treatment and health care and give people vitality and health. Spa and spa both refer to a way to make use of the water resources in spa combined with bathing to make people realize a healthier life. However, spa and spa are slightly different in implementation. Spa focuses on the application of technology and equipment, while spa is a kind of full-hearted enjoyment and atmosphere including vision, taste and touch.

The key of modern hydrotherapy is water resources and water equipment, such as barrel bath, wet steaming, dry steaming, shower and hydraulic massage bath. And minerals, seabed mud, flower extracts, plant essential oils, etc., are often used to improve water quality and act on the human body. SPA has different themes, some of which are mainly relaxation, soothing and detoxification; Some focus on bodybuilding and slimming; There are also heavy aromatic essential oils, marine living water or pure herbal therapies.