Infrared rays have strong penetrating power to human skin and subcutaneous tissue. The primary effect of external infrared radiation on human body is to raise the temperature of skin and subcutaneous tissue, promote blood circulation and metabolism, and promote human health [1]. The thermal effect, anti-inflammatory effect and promoting regeneration of infrared physiotherapy on tissues have been clinically confirmed. Usually, direct irradiation is used to treat diseased parts. Near-infrared micro-irradiation therapy has a significant effect on improving microcirculation, especially micro-blood flow. After irradiation, the blood flow velocity of capillaries is accelerated, the phenomenon of red blood cell aggregation is reduced, and the phenomenon of blood stasis in inferior papillary venous plexus is reduced or disappeared, which has a positive effect on improving the nutrition, metabolism, repair and function of body tissues and important organs [2].
At present, the mechanism of the secondary effect of infrared rays on human body is not completely clear.
Some scholars believe that far infrared rays can vibrate cells, mainly causing the vibration of water molecules inside and outside cells, activating cells and causing a series of biochemical and histochemical changes beneficial to health [1]. Some people think that far infrared rays with a wavelength of 8 ~ 14 micron can be called "life rays", which can significantly improve human microcirculation. When it acts on human water molecules, it can crack the aging macromolecules in the human body and recombine them into smaller water cluster. In this process, pollutants adsorbed on the surface of aging macromolecules are removed, the proportion of water increases, and water molecules attached to the surface of cell membrane increase, which enhances the activity and surface tension of cells. Due to the increase of water molecules penetrating the cell membrane, the activity of intracellular calcium ions is enhanced, thus enhancing the normal function of human cells and improving their bactericidal ability and immune ability. In addition, the light of life can also cut off the double or triple bonds of unsaturated fatty acids in blood, and saturated fatty acids are not easy to be oxidized into blood lipids [lipid peroxides], thus reducing the deposition of lipids in blood vessels and smoothing the blood vessel wall, thus reducing the occurrence of cardiovascular diseases or ophthalmic diseases such as arteriosclerosis and cataracts, and playing a good role in promoting human health.
Infrared rays in sunlight do different harm to the skin than ultraviolet rays. Ultraviolet light mainly causes photochemical reaction and photo-immune reaction, while infrared radiation causes reactions caused by molecular vibration and temperature rise. The thermal radiation caused by infrared rays can penetrate the skin more than ultraviolet rays. 25% ~ 65% of its radiation can reach epidermis and dermis, and 8% ~ 17% can reach subcutaneous tissue. Infrared rays have direct adverse effects on the skin through its thermal radiation effect, such as skin temperature rise, capillary dilation, congestion, and increased evaporation of epidermal water. Its main manifestations are red papules, premature aging of skin and pigment disorder. The skin temperature rises, the capillaries dilate and congest, and the epidermis water evaporates, which directly causes adverse effects on the skin.
Infrared rays can also enhance the damage of ultraviolet rays to the skin and accelerate the process of skin aging. Using the same sunscreen products and the same ultraviolet intensity, the SPF value (sun protection coefficient) measured in outdoor natural sunlight is obviously lower than that measured in laboratory artificial light source, which is caused by the dual effects of ultraviolet rays and infrared rays on the skin under natural sunlight. Infrared rays and ultraviolet rays have the same effect in accelerating tissue degradation. Infrared rays can also promote the development of skin cancer caused by ultraviolet rays. See /mph/ReadNews.asp for details? News ID=72