Heat Therapy

By: Alere Staff
Publication Date: Tue, 03/01/2016

Heat Therapy

Many people are huge advocates for heat therapy, or thermotherapy, to reduce pain. Adding heat to an injury can relax the muscles and reduce swelling. Overworked muscles become sore because of decreased blood flow and the buildup of a chemical called lactic acid.Applying heat helps by opening blood vessels and allowing more blood get to travel to the effected region and remove the lactic acid. This provides great relief and may be the recommended course of treatment for chronic pain.1,2

Heat therapy may not be the best solution for all injuries. According to various sources, it is ideal to use heat therapy for aches that are more than 24 hours old and other types of chronic, long-term pain caused by issues like arthritis, old sprains or strains, muscles spasms and muscle stiffness.1,2 Heat therapy may also be used for nerve pain conditions or back pains caused by disc problems. While there is little research that suggests heat improves the condition, it can still be comforting.2

If you apply heat directly after an injury, you can actually increase pain and swelling of the injured area. In the case of an immediate injury, ice is recommended over heat. Heat is also not recommended to treat irritated skin, open wounds and incisions that are still healing.2 People who have cancer are also not directed to use heat therapy as heat may cause increased tumor growth.2

Heat therapy can be applied either locally or systematically. Local heat is when heat is applied to a specific area with a hot water bottle or heating pad. Systemic heat therapy is the raising of your body temperature with a hot shower or bath, saunas or spas.1,2 It is important to exercise caution when applying heat for an extensive amount of time. Use these precautions when practicing heat therapy:

  • Protect yourself from direct contact with the heating device.
  • Wrap heat sources within a folded towel to prevent burns.
  • Stay hydrated during systemic heat therapy.
  • Avoid prolonged exposure to heat.  

Remember that heat therapy is not a substitute for a medical evaluation or proper treatment. Make sure to consult your physician for further treatment information.


  1. Hirsch, K.R., MD. Treating Pain with Heat and Cold. Healthline.com. July 9, 2014. Retrieved from the website: http://www.healthline.com/health/chronic-pain/treating-pain-with-heat-and-cold.
  2. Jacques, E. Using Heat for Pain Treatment. About.com. November 15, 2014. Retrieved from the website: http://pain.about.com/od/treatment/p/heat_therapy.htm