To prevent upper limb lymphedema, you need to protect your arm right after breast cancer surgery: (1) When you sleep, try to put your arm in a position higher than your heart, such as using a few pillows to cushion your arm to avoid its pressure. (2) You should move your arm frequently and do some simple household chores, but do not let your arm feel strained. (3) Do not carry heavy objects on your hands or shoulders, and try not to do work that requires a lot of effort from your arm muscles. If edema has occurred in the arm, do not expose the arm to direct heat, such as hot baths or long periods of sunbathing. The edema will be more powerful when the arm is heated.