Knowing whether to use ice or heat when you have pain is sometimes a tricky question. Both are excellent ways in which to treat an injury, but choosing the wrong method at the wrong time can lead your pain getting worse rather than better. The aim of this article is to remove the confusion of how ice helps, confirm which injuries are better suited to icing and clarify the most effective way to use ice as a “go-to” in your first-aid toolbox.
How does using ice work?
Ice, also known as cryotherapy, is primarily used to control pain. When you have an injury to a tissue, such as a tennis elbow (lateral epicondylitis) or a runner’s knee, the effected tissues become “inflamed.” Inflammation is triggered naturally within the body by chemicals within the blood stream. It is actually part of the natural healing process; the redness and swelling around the injury indicate there is a higher amount of fluid around the injury and within that fluid are various white blood cells, the basic components of your immune system (Manga et al, 2015). However, heat and swelling are also generally painful and, when excessive, can actually be detrimental to the healing process. Ice, when used properly, can provide an anaesthetic (pain numbing) effect in the same way that something like ibuprofen might work.
In addition to helping control pain, it also constricts the blood vessels so that those pesky inflammatory chemicals aren’t as easily able to enter the surrounding area (Galiuto, 2016) and continue the inflammatory process. Therefore it also works to reduce swelling and redness seen in acute injury. Heat, in contrast, would dilate (open up) the surrounding vessels making it easy for the inflammatory chemicals to travel and encouraging the process of inflammation to worsen.
What type of injury is ice good for?
Ice is good for fresh injuries like muscle strain (a tear in the fibre) or ligamentous sprain (Bleakley et al, 2004). You would want to be very careful using it if there was broken skin – in this case, we want a little inflammation to be present because you need the immune system to fight off invaders entering into the “hole” now present in your body! Additionally, you need to ensure that any treatment you introduce on broken skin is sterile so you are not putting yourself at risk of infection. But in most cases, if you have a fresh injury with unbroken skin and it is red, swollen and hot, ice is going to be your first step.
Ice can also help to reduce the pain of chronic repetitive injuries like carpal tunnel, plantar fasciitis, shin splints, tennis elbow, patella-femoral disorders (knee pain) and supraspinatus tendonitis (shoulder pain) (Wilson JJ and Best TM, 2005). NICE guidelines recommend ice or heat if you have wear and tear degeneration from osteoarthritis. Although heat feels nicer to apply, if you still have pain, ice is worth a go as it is cheap, won’t hurt you (unless you apply past numbness) and is better than constantly popping pain-killers which will cause side effects if taken in too-large doses.
What type of injury should avoid ice?
If you have muscle spasm, from my own anecdotal experience, ice can irritate this and make it worse. People often use ice on an acute low back injury, but these don’t often have inflammation associated with them. Often when you are talking about muscle pain, it is because of trigger points.
Trigger points could be thought of as muscle knots or mini-spasms. When they are present, they cause the entire muscle to tighten up. Trigger points are very painful and, unfortunately, very common around areas of injury. Exposing a trigger point to ice is usually going to cause aggravation and more pain.
Also, if you look at the lumbar spine, there is a significant amount of musculature overlaying the joints. This means it is difficult for ice to have the same anti-inflammatory effects as it would in an area more superficial to the skin, like at the top of your elbow. So, if you think the pain is some sort of a spasm, probably better to try heat instead as your first port of call.
What’s the best way to apply ice?
Ice packs can be used for approximately 10 minutes (or until the area goes completely numb) and then left off for at least 20 minutes before starting the cycle again. You want to ensure the ice is as close to the skin as possible – don’t wrap it in multiple layers of towelling as you are not going to receive a good effect. Use a thin towel so you can feel the cold but you are protecting your skin.
Ice “massage” can be undertaken for shorter periods of time – taking raw ice and rubbing it across the area until it is numb – which would take approximately 3 minutes. This may have a slightly faster pain relieving effect as it is a more direct application (Hawkins SW and Hawkins JR, 2016). You should never continue to ice past numbness as you can actually burn your skin if ice is applied too long. Repetitions are useful – icing only once or twice a day is probably going to be less effective than treatments taken on a higher frequency.
Galiuto, J (2016)The Use of Cryotherapy in Acute Sports Injuries. Annals of Sports Medicine and Research. 3(2): 1060.
Hawkins SW and Hawkins JR (2016) Clinical Application of Cryotherapy among Sports Physical Therapists. International Journal for Sports Physical Therapy. 11(1): 141–148.
Malanga GA, Yan N, Stark J. (2015) Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgrad Med. Jan;127(1):57–65
Wilson, JJ and Best, TM (2005) Common Overuse Tendon Problems: A Review and Recommendations for Treatment. Am Fam Physician. 72(5):811-818.