- Balneotherapy has been practiced for centuries in the management of autoimmune diseases. It is based on the indigenous natural remedies of the spas, such as thermal and mineral water, gases (CO2, radon) and peloids (fango, mud, peat). Thalassotherapy refers to the therapeutic effects of the seas and the climatic conditions existing at the spa area. In this article we review the proposed modes of action of balneotherapy on autoimmune diseases, and summarize published studies from Israel and Europe on its effect on different autoimmune diseases. The mechanism by which immersion in mineral or thermal water ameliorates autoimmune diseases is not clear. The net beneficial effect is probably a result of mechanical, thermal and chemical effects.