As the largest organ of body, skin has many functions as secretion, absorption, permeation, eccrisis and sensation besides resistance to exopathogens. Chinese herbal steaming therapy is designed to exert drug effect by making use of these physiological functions, that is, to have medicine absorbed through the superficial layer of skin, permeated through the horny layer and transferred through the corium layer into the blood circulation system. The absorption and permeation of skin is dependant on the humidity of air, which can be enhanced by the medical steaming.

To be specific, hot herbal steam may raise the skin temperature, induce skin capillaries to expand, promote blood and lymph circulation as well as metabolism and improve the nourishment of peripheral tissues. Meanwhile, the hot herbal steam may also have the pores open and sweat all over, forcing the pathogenic factors inside to be excreted to the outside of the body, which are helpful both in enhancing the body resistance and dissipating fatigue, bringing comfortable sense. On the other hand, the herbal steam may permeate acupuncture points and dredge the channels and collaterals while the steam are moving upwards, therefore, it can supplement qi, nourish the blood, regulate the balance of yin and yang and rectify immunity disorder. Natural herb is safe and environment-friendly in line with the trend that the development of drugs worldwide is turning direction from chemical compound medicine to natural officinal plants.

Chinese herbal steaming therapy has a very extensive application scope. For treatment of rheumatism and immune diseases, it can regulate the condition of immunity disorder so as to remove the cause of diseases. For treatment of scleroderma and rheumatic arthritis, the herbal steam may act directly on the region affected, softening skin, improving skin metabolism, relieving arthrodynia, inhibiting contracture of joints and preventing disease from expansion to the internal organs. It is therefore known as "skin dealysis". For treatment of muscular atrophy caused by polymyositis or dermatomyositis, it can activate blood circulation, supplement qi, nourish the blood, tonify the kidney and bone, nourish skin, and promote tissue regeneration and growth of muscular cells.