Whether it’s at home, at work, or in the gym, that age-old question of whether to use heat or ice for an injury continues to be debated. And there’s good reason for the debate, as there is no one correct answer to the question – it depends on the injury in question.
Below we describe the physiological and therapeutic benefits of both heat and ice to help you decide which one might be most effective to use.
Heat causes the blood vessels to open wide or dilate, which increases blood flow to the area to stimulate the healing process of damaged tissues. It also helps to relieve pain and spasm as a result of its direct soothing effect. It eases stiffness in connective tissue by increasing circulation and blood flow, resulting in more flexible and supple tissues.
Heat therapy is, therefore, useful to treat many health issues, including arthritis and muscle spasms, sprains, and strains. Heat should not be used on a new soft tissue injury, as it can increase bleeding around the injured area and may make the problem worse. An exception to this is new-onset low back strain. A lot of the pain, in this case, is caused by muscle spasm rather than tissue damage, so heat is often more helpful than ice.
The use of cold therapy or “cryotherapy” includes ice packs and ice massage (rubbing ice in a circular pattern directly over the affected area for 3-5 minutes). Cold therapy narrows blood vessels, a process called vasoconstriction. Vasoconstriction of blood vessels reduces the blood volume to the site of an injury, resulting in reduced swelling, metabolic rate, muscle spasms, and pain.
Ice treatment may be used in the immediate treatment of soft tissue injuries to limit the body’s response to injury. Ice will reduce bleeding into the tissues, prevent or reduce swelling (inflammation), and reduce muscle pain and spasm. These effects all help to prevent the area from becoming stiff by reducing excess tissue fluid that gathers as a result of injury and inflammation.
In the later phase of recovery, when the injury has healed enough to begin stretching and strengthening the area, ice can also help to restore normal function, enhancing other treatments by reducing pain and muscle spasm. Ice also provides a longer-lasting effect on circulation than heat, and the painkilling properties of ice are deeper and longer-lasting than heat.
Heat and ice can be used effectively on the same recurring injury, or even to prevent or lessen the severity of a possible injury. Heat would be used first to create circulation and allow the tissue or joint to be more mobile before exercising or starting an activity. Ice would best be used at the end of exercise or an activity to reduce any inflammation or pain that might arise. With repetitive use injuries like raking, shoveling, running, and hiking, tissue and joints need to be warmed up first to limit injury, and ice can be used afterward to slow down the inflammation and help with pain.
Ideally, ice should be applied within 5-10 minutes of an injury and used for 20 to 30 minutes; there is little benefit to be gained by leaving it on for longer, and it actually can result in damage to the skin. Apply heat to the area in question for 10-15 minutes at a time and check every few minutes to be sure that the skin is not getting too hot. Also know that if heat is applied directly to the skin, it should not be hot; gentle warmth will suffice. Both heat and ice can be re-applied after an hour if needed.
Do not use cold packs or heat over areas of skin that are in poor condition, sensitive to heat or cold, or have known poor circulation or infection. Please also note that using ice and cold packs from a deep freeze can cause ice burns quickly if used without proper protection.
If you have pain from an injury that is not improving with at-home treatment, contact your Atrius Health provider for a consultation.