During an ultrasonic cavitation procedure, noninvasive machines target specific body areas with low-frequency sound waves (they're what put the "ultrasonic" in "ultrasonic cavitation") and, in some cases, light suction. This process heats and vibrates the layer of fat cells below the skin's surface. The pressure eventually causes the fat cells to liquefy and release their contents into the bloodstream. Proponents of the procedure believe that the body is then able to process these fatty acids through its proverbial waste-disposal plant: the lymphatic system.