After twisting your foot, you need to apply ice packs for 24 hours, the main reason is that after the sprain, the blood vessels of the body rupture, rupture and bleeding lead to local blood accumulation, inflammation reaction aggravated, and then swelling, swelling stimulation of the surrounding nerves will appear pain. 24 hours of ice packs are mainly to reduce local bleeding, the principle is that ice packs can make the local skin temperature lower, the principle of thermal expansion and contraction leads to rupture of the capillaries contraction, contraction, after bleeding is reduced. After 24 hours, hot compresses are used to promote local blood circulation and metabolism, reduce the local inflammatory reaction as soon as possible, and further reduce the swelling.