Friends, family, and patients all ask me what to use on their aching back. What to use on their sprained knee. What to use after surgery and for how long, and how many times per day. In this article, I hope to shed a little light on these questions.

The first thing we all need to understand is what heat and ice do to your body. Heat causes your blood vessels to dilate (get bigger) and cold packs cause your vessels to constrict(become narrower).Both heat and cold will relieve pain. This is because pain and temperature impulses travel on the same "nerve freeway" to the brain. When you flood your nerves with temperature impulses (hot or cold),it prevents you from feeling pain.

Now let's discuss using heat versus cold. If you have a swollen,hot to the touch joint you must use ice. It will help bring down the swelling,and decrease the temperature and pain. When you get to the back or neck, it is harder to determine what to do because you cannot tell if there is any swelling. So here's a general guideline: if you wake up in the morning, and you are stiff and achy and there has been no recent injury, use heat. It will loosen things up and relax stiff muscles.

If you have had a recent injury to the neck or low back(whiplash,slip and fall, etc,), use heat in the morning to loosen up but only for 20 minutes or less. Then switch to cold packs as the day progresses. Ice will kill the pain and prevent swelling of tissues. Many of you may have heard to use ice only for the first 48 hours. I personally feel that because ice numbs out the joint, the pain relieving effect lasts much longer than it does with heat. Therefore, it is O.K. to use ice on a regular basis.

Personal preference plays a big roll in your choice of heat or ice. As long as there is no increase in the temperature of the joint or body part and there is no significant swelling, you can use heat on a regular basis. One area where heat is more indicated is with Osteoarthritis or Rheumatoid Arthritis. It is common for patients with these diagnoses to even have an aversion to icepacks or the cold.

Finally, how long and how often are the next items. When you apply heat or ice longer than about 30 minutes, the benefit becomes somewhat counterproductive. The blood vessels adapt to the temperature change and return to a normal size, i.e., not dilated or constricted. Therefore, it is best to ice or heat for 20-30 minutes per application. Regarding frequency of applications, it is dependent on the diagnosis/condition. If the condition is acute, the frequency should be every 2-3 hours and up to every other hour. For older injuries or chronic conditions, 2-3x/day should be sufficient.

Understanding the difference between and hot and cold packs can help your specific pain more than not being aware of the differences. As always, it is imperative that you follow the instructions of your physician or treating physical therapist. Click on the link to pull up a cheat sheet for how to use a hot or cold pack properly.