Spacer lipolysis for arm thinning is a non-contact treatment, through selective radio frequency technology, without damaging the skin and muscles, by transmitting high-frequency wave energy to the fat layer, inducing the natural death of fat cells and prompting their discharge from the body, so as to achieve the effect of slimming and slimming. Although the treatment is non-contact, there are certain risks, the specific risks are as follows: 1, pain: the treatment area of the patient will have slight pain during the process of spacer lipolysis, but most people can tolerate it; 2, hematoma: the larger subcutaneous cavity is filled with non-coagulable serum-like fluid, which may form a chronic hematoma. Small hematomas can be absorbed by themselves, while large hematomas need to be aspirated with a syringe or cut and released with pressure bandages; 3. Skin petechiae: they appear mostly within 24 hours after the end of treatment, and can disappear by themselves in 1-2 weeks, and generally do not need to be treated; 4. Skin burns: if the machine parameters are not set reasonably, resulting in high skin surface temperature will lead to skin burns, and skin necrosis can occur in individuals. Therefore, the operator should inform the doctor in time when he/she feels abnormal pain during the treatment; 5. Other complications: including skin numbness, pigmentation, subcutaneous hard nodes, bumpiness, etc., the incidence is low.