There are many reasons for swelling of the hand during injection, and the common ones in clinical practice are fluid extravasation and edema of the extremities caused by excessive fluid input in heart failure patients. Fluid extravasation is when the needle is not stuck into the blood vessels, or the needle is stuck into the blood vessels, but when the patient’s hand moves, the needle is displaced, and the fluid will seep into the subcutaneous accumulation to form local swelling, and some heart failure patients with excessive infusion will also have hand swelling, and this edema is symmetrical sunken edema. If the local edema is caused by fluid extravasation, rubbing the lump and heating the compress can speed up the dissipation of edema; if the edema of the extremities is caused by heart failure, attention needs to be paid to limiting the fluid input.