There are many types of hydrotherapy. They include:

• Pool. Swimming pools can be used to perform pain–relieving therapy. Therapy in a pool – which may or may not involve swimming – is beneficial to many patients because the buoyancy of water supports the body’s weight and removes the effects of gravity. This allows patients suffering from pain to perform low–impact exercises that are less stressful to the joints of the spine, legs and feet.

The support of the water also allows patients to move through their full range of motion more easily. At the same time, the water provides resistance that can help build strength and endurance.

A physician may recommend aquatic exercise therapy for patients who cannot tolerate high-impact activities. Research has shown that water aerobics can also relieve back pain and pelvic pain in pregnant women.

• Hubbard tank. These allow patients to immerse their entire body in water. Convection heating may be used to increase water temperature, facilitating range-of-motion exercises and easing conditions such as arm pain, shoulder pain, leg pain or back pain. Heating can cause blood vessels to dilate, increasing circulation. Therapy in a Hubbard tank can be particularly useful for burn patients, because temperature can be regulated and electrolytes can be added to the water.
  
  
• Whirlpool. This form of therapy involves heated, churning water that can help ease muscle sprains, chronic spinal conditions and wound debridement (excision of dead, devitalized or contaminated tissue). Jet nozzles in whirlpools release a mixture of warm water and air that massages the body and helps relax tight muscles.
  
  
• Sitz bath. The individual sits in a small tub with water covering the hips. Sitz baths may be advised for conditions such as lumbar pain, pelvic pain, prostatitis or testicular/scrotal pain.
  
  
• Saunas and steam baths. A physician may recommend these to ease conditions such as back strain or to relieve stress.
  
  
• Damp hot packs or cold packs. These types of thermotherapy and cryotherapy may be part of a physical therapy treatment plan. Moist compresses can be applied at home to ease conditions including migraines, facial pain and herniated discs. 

Some patients can obtain the benefits of water therapy at home by installing a pool or spa or using less expensive techniques, such as foot baths and damp compresses. However, home treatments must be performed correctly to be safe and effective. Patients must be sure that home pools can be entered and exited safely, and that thermometers are available to accurately measure water temperature. Patients should consult with their physician about details such as proper water temperature, suggested exercise routines and length of treatment sessions.