Most of the common arm hair removal procedures in the clinic refer to optical hair removal, which means that the laser energy reaches the vicinity of the hair follicle and the melanin in the hair absorbs a large amount of energy and increases in temperature, which leads to the destruction of the hair follicle tissue and the hair is removed. There is a slight stinging sensation during laser hair removal on the arms, and after the procedure there can be a mild burning sensation, mild localized skin erythema and follicular papules that can disappear within a few hours. Individual patients may experience purpura, blistering, temporary hyperpigmentation or hypopigmentation, most of which can recover in a few months. In addition, this procedure is not recommended for pregnant women because of the tingling and painful stimulation that may stimulate contractions. Advanced surface anesthesia, such as topical compound lidocaine cream, is often recommended in clinical practice for those who are particularly sensitive to pain; sun protection before and after the procedure, such as using sunscreen for more than 2 weeks; shaving the epidermis before the procedure, taking care to prevent scratching; and applying ice packs and topical skin care ointment during and after the treatment can reduce post-treatment discomfort and effectively reduce the chance of surgical risks. A small number of people can be sensitive to laser stimulation reaction, in order to avoid side effects, you can do a few spots of local trial treatment first, to determine no problem before large area treatment.