Postoperative numbness of fingers after breast cancer surgery may be caused by injury to nerves, hand compression caused by body position during surgery or lymphedema. 1. Damage to nerves: If the intercostal brachial nerves and sensory nerves of the upper limbs are injured accidentally during breast cancer surgery, the symptom of numbness of fingers after surgery may occur, which is usually difficult to be relieved in a short time, and it can be treated by vitamin B1, vitamin B12 and other medicines under the guidance of doctors. 2. Hand pressure caused by the position during surgery: breast cancer surgery usually adopts the prone position or lateral position, which may be due to the long-term pressure and ischemia of the hand during the surgery, resulting in nerve dysfunction caused by numbness of the fingers, which usually does not require special treatment, and can be relieved by elevating the affected limbs to promote blood return. 3. Lymphedema: If the lymph nodes are enlarged and cause return obstruction, it may also lead to numbness of fingers, which should be treated according to doctor’s instruction. Therefore, patients with numbness of fingers after breast cancer surgery should find out the cause of the disease as soon as possible and actively cooperate with doctors for treatment after diagnosis.