Saline is effective in reducing swelling because the osmotic pressure of saline is high, generally higher than the osmotic pressure of intracellular fluid, so this can be done by covering the wound directly with saline gauze or by infiltrating the affected area directly into the saline solution. However, if the concentration of saline is too high, it may cause the cells to lose water and become inactive, so it is recommended that patients go to the hospital to find a professional doctor for debugging to avoid damaging the cells due to the high concentration of saline. At the same time, if you want to reduce the swelling, you must elevate the affected limb as much as possible, which can effectively accelerate blood circulation, thus playing a rapid purpose of reducing swelling.