Heat therapy, also called thermotherapy, is the application of heat to the body for pain relief and health. It can take the form of a hot cloth, hot water, ultrasound, heating pad, whirlpool baths, hydrocollator packs, heat therapy wraps, and many others. It can be beneficial to those with arthritis and stiff muscles and injuries to the deep tissue of the skin. Heat may be an effective self-care treatment for conditions like rheumatoid arthritis. Heat therapy is most commonly used for rehabilitation purposes. The therapeutic effects of heat include increasing the extensibility of collagen tissues; decreasing joint stiffness; reducing pain; relieving muscle spasms; reducing inflammation, edema, and aids in the post acute phase of healing; and increasing blood flow. The increased blood flow to the affected area provides proteins, nutrients, and oxygen for better healing.
How Heat Therapy Works
Many episodes of pain result from strains and over-exertions, creating tension in the muscles and soft tissues around the body. As a result, this restricts proper circulation and sends pain signals to the brain.
Muscle spasms can create sensations that may range from mild discomfort to excruciating pain. Heat therapy can help relieve pain from the muscle spasm and related tightness.
Heat therapy application can help provide lower back pain relief through several mechanisms:
- Heat therapy dilates the blood vessels of the muscles surrounding the lumbar spine. This process increases the flow of oxygen and nutrients to the muscles, helping to heal the damaged tissue.
- Heat stimulates the sensory receptors in the skin, which means that applying heat to the lower back will decrease transmissions of pain signals to the brain and partially relieve the discomfort.
- Heat application facilitates stretching the soft tissues, including muscles, connective tissue, and adhesions. Consequently, with heat therapy, there will be a decrease in stiffness as well as injury, with an increase in flexibility and overall feeling of comfort. Flexibility is very important for a healthy bodies.
- There are several other significant benefits of heat therapy that make it so appealing. Compared to most therapies, heat therapy is quite inexpensive (and in many circumstances it’s free - such as taking a hot bath). Heat therapy is also easy to do - it can be done at home while relaxing, and portable heat wraps also make it an option while at work or in the car.
For many people, heat therapy works best when combined with other treatment modalities, such as massage therapy and exercise. Relative to most medical treatments available, heat therapy is appealing to many people because it is a non-invasive and non-pharmaceutical form of pain relief.
The most effective heat therapy products are the ones that can maintain their heat at the proper temperature. “Warm” is the proper temperature. Patients should not have their heat source be hot to the point of burning the skin. The desired effect is for the heat to penetrate down into the muscles. Simply increasing the temperature of the skin will do little to decrease discomfort.
In many instances, the longer the heat is applied, the better. The duration that one needs to apply the heat, though, is based on the type of and/or magnitude of the injury. For very minor injuries, short amounts of heat therapy may be sufficient (such as 15 to 20 minutes). For more intense injuries, longer sessions of heat may be more beneficial (such as 30 minutes to 2 hours, or more).
Two options of heat therapy include moist heat and dry heat.
There are many different manners for heat to be applied to the body. Some common options include:
- Dry heat, such as electric heating pads and saunas, draw out moisture from the body and may leave the skin dehydrated. However, some people feel that dry heat is the easiest to apply and feels the best.
- Moist heat, such as hot baths, steamed towels or moist heating packs can aid in the heat’s penetration into the muscles, and some people feel that moist heat provides better pain relief.
- Heated gel packs - may be microwaved, or sometimes heated in water, and tend to say warm for about 30 minutes. Certain types of gel packs provide moist heat, which some people prefer.
- Heat wraps - wraps around the lower back and waist and may be worn against the skin under clothing, providing convenience and several hours of low level of heat application.
- Hot bath, hot tub, sauna, steam bath - tend to stimulate general feelings of comfort and relaxation that may help reduce muscle spasm and pain. A whirlpool jet directed at the lower back may provide the added benefit of a light massage.
Finally, it is important to use enough insulation between the heat source and the skin to avoid overheating or burning the skin.
Please note that heat should not be used in certain circumstances. For example, if the injury is swollen or bruised, heat should not be used. Patients should consult doctors if they have heart disease or hypertension. Heat application is also not suitable in the following cases:
- Deep vein thrombosis
- Peripheral vascular disease
- Open wound
- Severe cognitive impairment
In general, if the injured area is swollen or bruised it is better to apply ice or a cold pack to reduce the inflammation or swelling.
In summary, heat therapy is an easy and inexpensive option to provide relief from many forms of pain. It may be used alone or in conjunction with other therapies. Because it is so simple, it is often overlooked and physicians may forget to mention it, but heat therapy used in the right way can be a valuable part of many pain treatment programs.