After breast cancer surgery, you can usually sleep on your side for about 24 to 48 hours, but be careful to favor the side that has not been operated on, otherwise it will compress the wound and is not conducive to recovery. Meanwhile, you have to judge whether you can sleep on your side according to your own situation and postoperative recovery. If the wound after breast cancer surgery is large, sleeping on the side may lead to wound tearing, which will have adverse consequences and affect the recovery of the affected area after surgery. Therefore, breast cancer patients should try their best to sleep on the right side, not on the side, and observe the wound situation in time so as not to squeeze the patient’s wound, and they can sleep on the side without surgery after about 24 to 48 hours of the operation with better recovery. If some breast cancer patients have axillary lymph node dissection surgery at the same time, try not to favor the affected side to sleep on the side, sleeping on the side may compress the veins of the upper limbs on the affected side and lead to reflux, which may lead to swelling. Whether patients can sleep on their side after breast cancer surgery should be based on the recovery of the body and the postoperative care under the guidance of the doctor.