Postoperative breast cancer patients need further treatment, need to infusion, in the end the affected arm can infusion this problem many patients are very concerned about, from the point of view of nursing norms try not to infusion in the affected arm. This is because after breast cancer surgery, most of the surgeries are modified radical surgery and lymph node dissection, which will cause local lymphatic reflux obstruction and venous reflux obstruction at the same time, and infusion on the affected side will aggravate the local reflux obstruction, which is easy to appear thrombus. Especially nowadays, most of the PICC infusion methods are used, and the PICC tube is contraindicated to be placed on the affected side, so it is not recommended that the patient be infused on the affected side. If the infusion is done on the affected side, it will aggravate the swelling of the limb, and there is a possibility of obstruction of venous return and lymphatic return, which will increase the chance of thrombosis. Considering the many factors, it is recommended that patients try not to infuse on the affected side to avoid aggravating edema and causing unnecessary trouble.