Can hot compress be used to relieve chronic pain? How long will it take to be effective?

In most cases, hot compress can be used to relieve chronic pain. The effective time ranges from ten minutes to three days, depending on the type of pain and the standard of hot compress.

I usually come into contact with many patients with this type of chronic pain. The most common ones are chronic lumbar fasciitis in sedentary people, shoulder and neck strain caused by long-term desk work, and cold legs in middle-aged and elderly people. If there is discomfort such as stiffness, swelling, and heaviness during the remission period of such problems, as long as there are no breaks in the local skin and the skin temperature is not high, hot compress is basically safe. There used to be a little girl who worked in design. She suffered from lower back pain for two years. When she didn't have an attack, she always felt like a wet and cold cloth was wrapped around her waist. Before, I always felt that it was only necessary to apply it if the pain was unbearable. Later, I was advised to apply a hot water bag at about 42℃ for 40 minutes every day before going to bed. After applying it for almost two consecutive days, the heavy and stiff feeling was basically gone.

However, not all remission periods of chronic pain are suitable for hot compresses. The most controversial ones now are the remission periods of gout and rheumatoid arthritis. If the uric acid control of gout patients is not up to standard, there will still be incompletely metabolized urate crystals in the local area. After the hot compress dilates the blood vessels, the crystals will be more likely to spread and irritate the surrounding soft tissues, which may induce an acute attack. I have met an uncle with a history of gout for 5 years. During the remission period, his ankles felt stiff. I applied a hot water bottle at home for half an hour, but the pain was so bad that I couldn't get off the ground that night. As for the remission period of rheumatoid arthritis, if the joint skin temperature is still higher than the surrounding normal skin, it means that there is still hidden aseptic inflammation. There are currently two different views in the academic circles. One group believes that hot compress can promote circulation and accelerate edema metabolism. The other group believes that hot compress will dilate blood vessels and aggravate inflammatory exudation, which will in turn make the joints more swollen. In this case, it is prudent to ask your attending doctor before applying blindly.

As for how long everyone is concerned about taking effect, the difference is actually quite big. If it is just chronic soreness caused by muscle tension and spasm, as long as the temperature is controlled between 40 and 45 degrees Celsius, not too hot or too warm to be ineffective, you can basically feel the muscles loosen significantly after applying it for more than ten minutes, and most of the painful tightness can be eliminated. ； If it is discomfort caused by bone and joint problems such as degenerative knee arthritis and chronic synovitis, you may have to apply it for 2 to 3 consecutive days, two or three times a day for about 20 minutes each time, so that the feeling of heaviness when walking and pain when catching cold will slowly subside.

By the way, one more thing to mention: when applying hot compresses, do not apply hot water bottles or warm patches directly to the skin. Especially patients with diabetes or peripheral neuropathy are not sensitive to temperature and can easily be burned by low temperature. It is safest to put a thin towel on them. If you still don’t see improvement after applying it for 3 days, or even the discomfort gets worse, don’t force yourself to do it, go to the hospital to check if there is any problem that has not been discovered. After all, hot compress is just a small way to assist relief, and it cannot replace regular treatment.