Swelling and blistering of a fall injury may be due to an inflammatory reaction in the local tissues or drug stimulated blistering. 1. Inflammatory reaction of local tissues: especially in the acute stage after a fall, due to the rupture of tissue cells and capillaries in the injured area, there will be edema, increased tension and other abnormalities. The surrounding local venous return will be affected and oozing will occur, then blistering will occur. 2. Drug stimulation blistering: if the fall immediately after the wound in the use of stimulating drugs, resulting in skin allergic reaction, the tissue trauma coupled with an allergic reaction, can cause the local tissue fluid seepage to the subcutaneous, resulting in swelling, blistering. Swelling and blistering from a fall requires prompt medical attention by a professional doctor according to the specific situation.