Most of the fat in the upper arm accumulates on the inner side and the back side of the upper arm, but in order to get a better shape, the superficial fat on the inner side and the outer side should be sucked, while the middle part of the back side of the upper arm is easy to sag, so it is necessary to avoid repeated suction when sucking. In addition, the posterior side of the upper arm is very close to blood vessels and nerves, which requires high experience and skills of doctors. It is suggested that it is best to choose a regular hospital with technical advantages.