DOES ICE OR HEAT HELP INJURIES HEAL FASTER?
Ice and heat are convenient home remedies used to reduce pain. When deciding which one to choose you should consider the potential effects of each one on the healing process. The conventional use of ice, particularly in the first 24-48 hours following injury, soothes the pain and slows the bleeding into the injured area, but some experts suggest that its effects on the circulation might slow the natural rate of the healing process. Heat stimulates the area to respond in ways that seem to promote healing but the current research is lacking direct evidence that it influences recovery time.
THE CONTROVERSY AROUND ICING INJURIES
Sports Medicine physician, Gabe Mirkin, MD, coined the mnemonic RICE for Rest, Ice, Compression, and Elevation as the first aid approach to sports injuries in 1978. Ice has been the standard recommendation for treatment of injuries ever since. Ice seems to make sense because the body responds as follows: blood vessels constrict to effectively reduce hemorrhage and swelling; nerve endings are numbed to provide pain relief; and, if applied intensely enough, the painful inflammatory response is suppressed.
In 2014 Dr. Mirkin reversed his stance regarding the use of ice on injuries in his online article “Why Ice Delays Recovery”. His new theory is based on his sports medicine experience and a literature review published in The American Journal of Sports Medicine in 2004 that concluded that there was no definitive evidence that ice provides any healing benefit. He also cites studies that suggest the body’s response to cold of reducing blood flow to the area hampers the delivery of healing immune factors to the injured tissue and suppresses the inflammatory stage required for healing. A 2014 study on deep cold therapy methods cautions that deep methods of cold-induced blood vessel constriction risks cellular damage due to prolonged lack of oxygen in the tissue. In the field, our experience is that ice helps reduce pain, but since pain is measured by individual perception the evidence is anecdotal.
WHAT ABOUT HEAT?
Heat is also a convenient home remedy for pain. In the first few days following injury heat is generally discouraged as the belief is that it will increase painful inflammation; however, when applied at moderate intensity there is no evidence that heat causes any harm. In fact, it is questionable whether it penetrates the tissue deep enough to influence the inflammatory process.
According to a literature review published in Postgraduate Medical Journal in 2015 , “The physiological effects of heat therapy include pain relief and increases in blood flow, metabolism, and elasticity of connective tissues.” These effects sound beneficial for healing, but currently there are no studies that conclude that heat improves recovery time.
The Chinese Medicine model, which is centuries old, prefers heat over cold when treating injuries. The theory is simple: heat encourages circulation and cold restricts it; circulation is required for tissue repair so cold is never recommended for injuries.
I recommend heat over ice for pain in most situations, except within the first day following injury when heat may exacerbate bleeding into the injured site. In that stage I would agree with Dr. Mirkin’s current advice of elevation and compression, adding gentle active motion as tolerated. Active motion by itself encourages circulation; active motion combined with elevation assists in the flow of lymphatic fluid carrying dead cells and debris away from the injury. Notice that Dr. Mirkin has replaced total Rest in the RICE model with gentle motion.
In my clinical experience, I have found that heat eases muscle stiffness and pain, encourages mobility of arthritic joints, deactivates painful trigger points in the back and neck, soothes tendonitis and bursitis, and helps relax muscle spasms. I recommend heat because: there is no evidence that warming the tissue causes any harm; patients tend to find heat more agreeable than cold; and the increased circulation to actively healing tissue seems like a good idea.
USE CAUTION WHEN APPLYING HEAT OR COLD
Caution is advised when applying hot or cold, because extreme temperatures can damage the skin. Our pain tolerance will protect us from this in most cases but burns and frostbite are a risk if one ignores those painful burning signals or has impaired sensation. Warm baths, heating pads, and microwaveable rice bags are all soothing methods of home therapy. The temperature should feel warm — not hot. The skin should be monitored regularly during application of either ice or heat. Never sleep on a heating pad.
The next time you consider applying ice to an injury, be wary of intensely chilling the tissue and remember that cold interferes with your body’s natural inflammatory response that is required for healing. If your intent is to limit the initial bleeding into the injured site, remember that compression and elevation are also effective means toward that goal.