According to a publication from The Arthritis Foundation, Spas, Pools, and Arthritis (USA), "Regular sessions in your hot tub help keep joints moving. It restores and preserves strength and flexibility, and also protects your joints from further damage. Exercise can also improve a person's coordination, endurance, and the ability to perform daily tasks, and can lead to an enhanced sense of self-esteem and accomplishment."

"A hot tub fulfills the need perfectly . . . providing the warmth, massage, and buoyancy that is so necessary to the well-being of arthritis sufferers. The buoyancy of the water supports and lessens stress on the joints and encourages freer movement. Water exercises may even act as a resistance to help build muscle strength."

The Wall Street Journal reports that Japanese doctors are recommending soaking in hot springs for their patients with arthritis, saying that the warmth and chemical content of the springs can relieve arthritis symptoms and provide benefits that last longer than soaking in a regular hot water bath. Similar treatments are offered in a handful of hot spring sites in the US as well.