Q. I have a lot of discomfort from osteoarthritis. A friend suggested heat therapy. What is heat therapy, and does it work?
A. Yes, heat therapy can help relieve the pain and stiffness of arthritis.
Heat therapy is based on the idea that heat raises your pain threshold. That means that it takes more pain before you feel the same level of discomfort. Heat also relaxes muscles, and tense muscles are a common cause of pain.
One of the best things about heat therapy is that you can do it yourself. You don't necessarily need professional treatments.
For example, warm baths (hydrotherapy) are used by many physical therapists, but hydrotherapy can also be done at home. A hot tub or a bathtub equipped with water jets can closely duplicate the warm-water massage of whirlpool baths used by professionals.
Of course, oversized tubs are expensive. For most people, the bathtub works nearly as well. Soaking for 15 to 20 minutes in a warm bath exposes the body to warmth and allows the weight-bearing muscles to relax.
A warm shower may also help. Consider getting an adjustable showerhead massager. They're inexpensive and easy to install. It should deliver a steady, fine spray or a pulsing stream, with a few options in between.
One thing I emphasize with my patients is to dress warmly after a shower or bath to prolong the benefit. You need to hold in the heat.
I remember a patient of mine, a man in his 50s, who suffered from muscle spasms and loved to take long, hot baths and showers. Whenever he got out of the bath or shower, he felt so great that he celebrated. He did this by doing stretching exercises "in the buff" (he lived alone). The stretching exercises were a great idea: When relaxed by heat, muscles are stretched more easily. But the "in the buff" thing was a bad idea. With his body needing to keep a temperature of 98.6 degrees F, and his apartment at 70 degrees, his loosened muscles tended to stiffen pretty fast.
A heating pad is another good idea -- and keep in mind that moist heat penetrates more deeply. You can purchase hot packs and moist/dry heating pads, but a homemade hot pack works just as well. Heat a damp, folded towel in a microwave oven for 20 to 60 seconds or in an oven set at 300 degrees F for five to 10 minutes.
To prevent burns, always test the heated towel on the inside of your arm before applying to a joint: It should feel comfortably warm, not hot. To be extra-safe, wrap the heated towel in a thin, dry one before placing it on the skin.
We have a lot more information on other self-help strategies for osteoarthritis besides heat in our Special Health Report, "Arthritis: Keeping Your Joints Healthy." You can find out more at my website.
• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.