Ice is a fantastic therapy that you can do at home at any time. It is one of the few therapies that "if some is good then more is better."
Many people have seen someone sprain their ankle and it becomes immediately swollen and tender. Within a few hours the ankle can swell to several times its normal size. Some people may joke about a scene from The Nutty Professor in which Eddie Murphy/The Professor's limb doubles in size.
Spraining your ankle causes damaged cells to release inflammatory chemicals that cause fluid to leak out of blood vessels and into injured tissue. The body is trying to protect itself by limiting your ability to walk or run on the injured ankle and keeping you from causing more damage. The inflammation also increases pain levels and makes you more sensitive to normal pressure.
Inflammation is a protective process. Some inflammation is good, but too much inflammation slows down the healing process. When ice is applied to the skin it decreases skin and tissue temperature. A lower temperature slows cellular metabolism and the inflammatory cascade, in addition to decreasing pain.
Compressing ice against the ankle transfers more of the cold into the ankle. Combining ice with elevating the ankle above your heart will further reduce swelling from accumulating. Ice should be applied in cycles of 15 minutes. Place an ice pack on the ankle for 15 minutes and then take it off for 15 minutes to let the ankle warm up. Repeating this process 5-7 times a day will significantly decrease the overall size and amount of swelling.
You may think of P.R.I.C.E for an acute injury: protect, rest, ice, compress, and elevate. However ice also works with chronic injuries. People with chronic neck or low back pain have less pain when they ice during the day. Ice will decrease muscle spasms and pain associated with chronic injuries. It limits the small amounts of inflammatory molecules that are produced with chronic injuries from accumulating.
We recommend ice to people but they are usually hesitant because it is "cold." Trying to talk people into icing three times a day seems like an impossible task. People naturally prefer heat and don't like the shock and cold of ice. After reluctantly icing for a few days and feeling the results, people learn to like it and the decreased pain and muscle fatigue it offers.
Icing will decrease swelling and pain levels while speeding up your recovery. When in doubt, put ice on it. Ice is your friend!