The term "hydrotherapy" refers to any therapy program that uses water on the outside of the body (as opposed to inside of the body—for example, drinking water). Hydrotherapy can take many forms, such as:
- Sitting in a hot whirlpool to warm up joints
- Prescribed, supervised physical therapy that takes place in a pool
- Doing water aerobics or swimming laps to build strength
Hydrotherapy is not limited to people with arthritis or joint injuries. For example, many serious athletes use ice baths to recover from workouts.
Advantages of Hydrotherapy
Many of the advantages of hydrotherapy are due to hydrostatic pressure—water pressing against a submerged body from all sides. Water even exerts force upwards, against gravity, which is why the body feels lighter in water (buoyancy) and may be able to float.
- Takes stress off weight-bearing joints. Buoyancy in water results in less pressure on joints.
- Improves blood circulation. Water’s hydrostatic pressure acts as a compression stocking, improving blood circulation.
- Increases heart function. Improved blood circulation helps the heart work more efficiently, pumping more blood at fewer beats per minute. (An individual’s target heart rate is typically lower in water than on land.)
- Provides added resistance, which can help build muscle. Even simple movements, such as walking, are more challenging when in waist- or chest-deep water.
In addition to the physical benefits caused by hydrostatic pressure, exercising in water seems to improve mood and emotional well-being. Small research studies suggest that regularly exercising in water may help reduce symptoms of depression and anxiety1-3 and even encourage better sleep.4,5
Warmer water may feel better on stiff joints
While water temperature is a matter of personal preference, warmer water is considered better for loosening stiff joints. Pools specifically designated for therapeutic exercise may be kept at higher temperatures than pools primarily used for lap swimming.
Swimming ability is not required
Aquatic exercise can be done in waist- or chest-deep water, so swimming skills are not necessarily required. Regardless of swim abilities, an instructor or lifeguard should always be present.
Whirlpool Therapy, Hydromassage, and Balneotherapy
Not all forms of hydrotherapy require physical activity. Passive forms of hydrotherapy may reduce pain and loosen stiff joints. They may also be relaxing and improve mood. A few examples include:
- Sitting in a hot water whirlpool for 5 to 20 minutes warms up stiff joints. It may also be relaxing and improve mood.
- Hydromassage, or water massage, typically involves sitting or lying down in a water-jet tub. The water jets can be aimed to apply pressure to stiff and painful areas.
- Balneotherapy is slightly different than hydrotherapy because it uses mineral waters and muds rather than tap water. While proponents believe the minerals provide added benefits, the science is uncertain.6-8 This type of therapy is typically offered at facilities advertised as medical spas.
People with weakened immune systems are advised to ask about facilities’ cleaning and maintenance routines.9
Ultimately, individuals must decide what works best for their bodies and health circumstances. For example, spending time in a hot whirlpool is discouraged if joints are inflamed.
While considered safe, there is not a lot of research for or against passive forms of hydrotherapy. In contrast, active forms of hydrotherapy have established benefits.