How does hot & cold therapy really work to reduce swelling, manage pain and help promote faster healing?

The injury

After an injury, ligaments, tissue and blood vessels could be damaged. The body’s healing mechanism causes cells around the injury to increase their metabolism in an effort to repair the damaged area. As a result of increased metabolism they need more oxygen, but due to damaged blood vessels and increased fluid there is a lack of incoming oxygen and waste removal. When the cells cannot get the required oxygen in and waste out they begin to die. This causes blood and fluids to begin to pool in spaces around the injury causing additional swelling pain and bruising.

Cold application

Cold therapy is applied to an injury in order to reduce the temperature of the damaged tissue area. This temperature reduction causes a chain of events to occur. The cells’ metabolic rate rapidly slows causing them to use less oxygen. They now remain alive. As the local blood vessels constrict, this aids in slowing the flow of fluids to the injury site. Swelling is reduced. The reduction of cell damage is the key to cold therapy. By keeping more cells alive in the damaged area we can decrease bruising and fluid buildup. Also, with fewer damaged cells to repair and rebuild your body can recover faster. The numbing of the nerves by cold applications serves to reduce the amount of pain you experience. Its best to use cold applications immediately after an injury.

Heat application

Heat therapy is most beneficial in the repair stage of an injury. This is usually greater than 72 hours after the initial injury. Heat helps increase the blood flow to the tissue, thus helping the cells rebuild faster. Sore, overworked and tight muscles can benefit from heat therapy. Heat should not be applied to acute injuries or anywhere internal bleeding, discoloration or swelling is present.