Chronic pain can be extremely disruptive daily life. It can limit our ability to focus, reduce the quality of our sleep, and diminish our ability to enjoy our favorite activities or time with our loved ones. Unfortunately, this kind of lasting, disruptive pain is a really common problem. One in three Americans are affected by chronic pain every year and it’s one of the main reasons people seek medical treatment (B Cotler, 2015). Typical treatment often involves prescription drugs that can be pretty risky to use regularly and can’t provide long-term relief. Luckily, there is another option: Red light therapy. Research shows that red light is a safe, effective, and lasting treatment for pain of all sorts, from arthritis to toothaches (de Sousa et al., 2018).
The remarkable ability of red light to relieve pain has been studied by scientists for decades. There is now a wealth of studies demonstrating its efficacy for treating chronic neck pain, tendonitis, rheumatoid arthritis, plantar fasciitis, carpal tunnel syndrome, tooth sensitivity, and much more (B Cotler, 2015). Scientists are still working out exactly how red light is able to provide pain relief from such a variety of causes, but one way red light therapy is thought to reduce pain is actually pretty clever. It simply prevents perception of pain by blocking painful sensations from traveling to your brain (Pires de Sousa et al., 2016).
For us to feel any kind of physical sensation, sensory information has to travel from the part of our body where the sensation occurs to our brain where that information is translated into our perception of the physical sensation. For example, when someone taps you on the shoulder, pressure sensors in your skin transmit that sensory information from your shoulder, up through your spinal cord, and to your brain. Once the information reaches your brain, you become aware that someone has just tapped you. Pain works in exactly the same way. Information about a painful sensation is transmitted from your body to your brain along specific types of nerve fibers, called C-fibers. Activation of C-fibers is one of the primary sources of pain. These fibers can be activated by many different types of stimuli, most notably the molecules that cause inflammation. This is partly why swelling hurts so bad. Inflammatory molecules activate C-fibers, which then essentially tell your brain “ouch!”. However, if those painful signals never reach your brain, you don’t feel the pain. This is where red light works its magic. Red light is well-known to reduce inflammation. Reduction of inflammatory molecules leads to reduced activation of C-fibers and ultimately to lessening of pain perception. This function of red light has been validated through science. For example, a study investigating the effects of red light therapy on arthritis of the knee, a disorder associated with pain and inflammation of the joint, found that treatment with red light significantly reduced markers of inflammation as well as perception of pain (Pallotta et al., 2012). Other studies have found that activity in the C-fibers is significantly slowed following treatment with red light, supporting the hypothesis that red light reduces pain by inhibiting C-fiber activity (Chow & Armati, 2016).
Chronic pain is, well, a pain to deal with. It can reduce the quality of every part of our lives if left untreated, but the typical treatments can be just as troublesome as the problem and aren’t suitable for long-term use. Red light therapy is a safe and effective alternative to drug therapies and can be used long-term without any side-effects (de Sousa et al., 2018). There are likely many ways that red light helps to relieve pain, but one way is simply by limiting the transmission of painful sensations to your brain. Basically, if your brain never gets any pain signals, there isn’t any pain. One of the many amazing benefits of red light therapy.
B Cotler, H. (2015). The Use of Low Level Laser Therapy (LLLT) For Musculoskeletal Pain. MOJ Orthopedics & Rheumatology, 2(5). https://doi.org/10.15406/mojor.2015.02.00068
Chow, R. T., & Armati, P. J. (2016). Photobiomodulation: Implications for anesthesia and pain relief. Photomedicine and Laser Surgery, 34(12), 599–609. https://doi.org/10.1089/pho.2015.4048
de Sousa, M. V. P., Kawakubo, M., Ferraresi, C., Kaippert, B., Yoshimura, E. M., & Hamblin, M. R. (2018). Pain management using photobiomodulation: Mechanisms, location, and repeatability quantified by pain threshold and neural biomarkers in mice. Journal of Biophotonics, 11(7), e201700370. https://doi.org/10.1002/jbio.201700370
Pallotta, R. C., Bjordal, J. M., Frigo, L., Leal Junior, E. C. P., Teixeira, S., Marcos, R. L., Ramos, L., De Moura Messias, F., & Lopes-Martins, R. Á. B. (2012). Infrared (810-nm) low-level laser therapy on rat experimental knee inflammation. Lasers in Medical Science, 27(1), 71–78. https://doi.org/10.1007/s10103-011-0906-1
Pires de Sousa, M. V., Ferraresi, C., Kawakubo, M., Kaippert, B., Yoshimura, E. M., & Hamblin, M. R. (2016). Transcranial low-level laser therapy (810 nm) temporarily inhibits peripheral nociception: photoneuromodulation of glutamate receptors, prostatic acid phophatase, and adenosine triphosphate. Neurophotonics, 3(1), 015003. https://doi.org/10.1117/1.nph.3.1.015003