Warm water therapy has proven beneficial for FM pain. A hot tub helps relax muscles and the water decreases resistances, which may help prevent development of myofascial trigger points with water physical therapy, as long as you don't overdo.
Use caution if you have chemical sensitivities. Hot water requires more chemical control to maintain ph balance and control bacterial growth.
If you have problems with frequent urinary tract infections, submersion in any water, including the bath tub, is not recommended.
Find out more about this book:Integrative Therapies for Fibromyalgia, Chronic Fatigue Syndrome, and Myofascial Pain: The Mind-Body Connection