(from Greek pelos, clay, mud, and therapeia, treatment), therapeutic use of mud from various sources and of mudlike substances (such as paraffin and ozokerite).

Bottom sediments from heavily mineralized bodies of water (sulfide muds), bottom sediments from bodies of fresh water, well-decomposed peat (mineralized and freshwater), and, less commonly, volcanic muds are used in pelotherapy. The various kinds of mud differ greatly from one another with respect to the conditions under which they were formed, the original material, and the chemical composition. Therapeutic muds have such characteristics in common as high colloidality, which makes the mud highly hydrophilic and leads to an absence of thermal convection, high heat capacity, and high heat-retention capacity. Besides thermal action, mud has a chemical effect on the body by stimulating the thermoreceptors and chemoreceptors embedded in the skin. Owing to the penetration of certain chemical substances (such as gases soluble in lipids) through intact skin, pelotherapy stimulates connective tissue and endocrine gland secretion, intensifies the blood flow to the skin and to local pathological foci, helps to intensify metabolism and the regenerative and repair processes, and exerts analgesic, re-sorptive, and desensitizing effects.

The application method of pelotherapy is the method most used in the USSR. Local applications are most common; in them mud is applied not to the entire body but to certain parts, for example, to the hands (“gloves”), hands and forearms (“high gloves”), feet and talocalcaneal joints (“socks”), lower part of the trunk (“trousers”), and to the neck and shoulders (“collar”). In gynecological practice, mud can also be introduced into the vagina. In some chronic diseases of the large intestine and some diseases of the male and female genitalia, mud is introduced into the rectum. In treating patients, mud treatment may be combined with the simultaneous application of an electric current (galvanic pelotherapy, diathermic pelotherapy, diathermic-galvanic pelotherapy, and mud inductotherapy). Mud procedures are carried out every other day or two days in succession with a break on the third day. The temperature of the mud ranges from 37° to 46° C, and the mud application is effective for 15 to 20 minutes, less frequently 30 minutes.

Pelotherapy is used in chronic and subacute inflammatory diseases of the supportive and locomotor apparatus resulting from metabolic disorders and functional impairment of the endocrine glands, diseases and sequelae of injuries to the peripheral and central nervous systems, sequelae of traumatic lesions, inflammatory diseases of the male and female genitalia, inflammatory diseases of the digestive organs, residual effects of burns and frostbite, some skin diseases, and so forth. Pelotherapy is contraindicated for acute inflammations, tuberculosis, heart failure in the decompensation stage, pronounced atherosclerosis, hypertension, varicose veins, blood disorders, chronic and functional diseases of the kidneys, and so forth. Pelotherapy is administered in specially equipped pelotherapy centers. Among the health resorts that are well known in the USSR for their mud baths are Saki, the Odessa estuaries, Slaviansk, Lipetsk, Druskininkai, Krainka, Piarnu, and the Caucasian Mineral Waters region.