Hydrotherapy is the use of water in any form for therapeutic purposes. It can help decrease pain, lessen swelling and improve circulation due to the physiological effects of the "vasoconstriction" and "vasodilation," or narrowing and widening, of blood vessels in response to temperature change.

Don't use hydrotherapy on open wounds or rashes, or if you suffer from cardiac conditions, malignancy, lymphedema or any undiagnosed health conditions. Hydrotherapy techniques should only be used with medical supervision if you have compromised circulation or sensation.

Hot water or cold water?
The best rule of thumb is to use only cold hydrotherapy techniques on acute injuries within 24 to 72 hours of injury. An acute injury is a bump, bruise or sprain that you can attribute to a particular, usually painful, accident or incident. Signs of acute injury include pain, redness or other discoloration, swelling and heat. (If symptoms persist or continue to worsen, you should seek medical evaluation.) Treating an injury with cold hydrotherapy at this stage may help minimize pain and swelling and can actually help speed healing.

If the injury is older than a few days and the swelling, redness and pain have diminished, or if you're just treating an ache or pain that resulted from "overdoing it," then you can choose either warm or cold hydrotherapy.

Ice is often too intensely cold for most of us to use long enough to gain therapeutic benefits. And for some people, ice's extreme reduction in temperature can provoke reactions such as nausea, anxiety, tension and discomfort. (Immediately discontinue your hydrotherapy treatment if you experience any of those effects.) To avoid such side effects, you can use cool water (65 to 55 degrees), skip the ice, and still get the benefits of vasoconstriction and vasodilation.

Warm hydrotherapies should be kept below 105 degrees because of the danger of burns at higher temperatures. Relaxation and vasodilation can occur at temperatures as low as 80 to 90 degrees, so longer or more frequent treatments are usually preferable to higher temperatures. Once you've picked your temperature range, you can choose a method. Two simple home hydrotherapy treatments are immersions and compresses.

Immersions
Fast, simple and requiring almost no equipment, immersions are most effective when you can completely soak a target area. They're great for treating sore feet, tired or cold hands, and aching ankle, wrist and elbow joints.

To create an easy immersion, grab a large bowl or a dishpan. First check for fit, then fill it with your chosen temperature of water. Now place the container in a convenient spot -- normally the floor for feet and lower legs, and a table, couch or chair for immersion of hands or arms -- and soak for 10 to 20 minutes. Remember to have a towel handy for keeping water off the floor and furniture.

Consider adding scented soap (peppermint is great for foot treatments) and bath or Epsom salts (very popular with soaking veterans). Relax. Enjoy.

Compresses
More convenient than immersions, since they require less water and are more portable, compresses are great for relieving tension headaches, abdominal cramping, back pain, sore muscles and minor injuries. They work on extremities as well as on areas that aren't as easy to soak, like the shoulder, upper leg, hip, trunk and neck.

To make a basic compress, soak a medium-sized towel in warm or cold water, wring out the excess, and apply to the chosen area for 10 to 20 minutes. When the compress returns to room temperature, simply re-soak and reapply.