Mud is a natural product formed by organic and non-organic compounds through various chemical, biological and microbiological processes in a liman lake. Mud has a specific fine structure, high plasticity, alkaline reaction and hydrogen sulfide smell. The essence of mud treatment is in its nature a complex effect of all factors of medicinal mud, where a main role is played by the thermal, chemical and mechanical factors. Medicinal factors have a specific effect on the body mainly in a neuro-reflector way, unlocking intimate adaptive reactions, most importantly by endocrine mechanisms and hypothalamo-hypophyseal adrenocortical, hypophysis-thyroid, simpatico-adrenal chains. Procedures with medicinal mud lead to significant activation of metabolite processes.