Laser hair removal is through selective photothermolysis, penetrating the skin directly to the root of the hair follicle, causing irreversible destruction of the hair follicle structure, so as to achieve the effect of inhibiting hair regeneration. If due to personal physical factors or do not pay attention to the operation method, etc., may also produce side effects, specifically the following aspects: 1, hair removal site redness; 2, some patients may show follicular edema, the skin appears small wind-like changes; 3, if the laser energy is too high or repeated treatment, hair removal site may appear blister, or even crust, scarring, etc.; 4, because the hair follicle and sebaceous glands are close to each other, laser hair removal may affect the sebaceous glands, resulting in less oil production and slightly poorer skin moisturization in the post-hair removal area. To sum up, it is recommended that patients perform local cooling after hair removal, which can reduce local discomfort reactions. If you find that the redness of the skin persists after hair removal, or even blisters appear, you should go to the hospital promptly and have it treated by a doctor. If only slight local redness and follicular edema occur, they can disappear in 1-2 hours after treatment in most patients. It should be noted that the degree and amount of hair reduction varies from person to person, and some people can achieve satisfactory results very quickly, while others need more treatments than regular cases, which should be determined on a case-by-case basis.