Sulfur baths are considered the most active method of balneotherapy. These baths, distinguished by their specific effects on each body, have thermal and hydrostatic effects, as well as a strong local effect, which is due to the free and semi-combined sulfur contained in sulphurous waters. The effect of sulfur is not only limited to the skin level, but also affects the internal organs by penetrating through the skin and air-permeable mucous membrane.

Sulfur irritates the skin receptors, stimulates movement, breathing and other centers, stimulates reflex reactions. As a result of studying the pharmacodynamics of sulfur, it was found that 50% of the sulfur taken from baths is stored in the skin and after 1 hour it is removed from the body mainly through the kidneys (80%) and a part through the skin (20%). Sulfur circulating in the blood is quickly oxidized with the participation of the liver, and the oxidation products are removed by the kidneys. Therefore, sulphide balneotherapy is contraindicated in liver and kidney diseases. Thus, complications may be observed by these organs. By changing the osmotic pressure of the skin, sulfur baths cause the formation of vasoactive substances of protein origin, which ensures tissue homeostasis.