The purpose is to reveal functional violations of various organs and systems at persons who have suffered from diphtheria and to develop algorithm of medical examination. Material and methods: 10 years» observation of over 722 patients who have had diphtheria has been made. Nuclear heating plants, ALT, glucose, urea, creatinine, troponin, blood myoglobin, creatinine of urine, SKF, LPI, anti-toxic antibodies, organ authoantibodies, interferons, AKTG, a corti-sol, TTG, ТЗ, T4, insulin and S-peptide, authoantibodies to thyroglobulin have been determined, an electrocardiogram, Doppler — and an echocardiography have been carried out. Results: It is revealed that at 59% of the persons who have had diphtheria, in the first three years catamnesis included the pathology of cardiovascular, nervous and urinary systems caused by existence of complications and a form of diphtheria in the acute period was created. It was accompanied by violation of functions of immune and hormonal systems: there was no protective anti-toxic immunity, autoimmune process was started, activity of the central and vegetative endocrine glands decreased. Depending on extent of these violations various options of disturbance of adaptation have been developed. At 5% of patients disturbance of adaptation resulted in lethal outcome. Conclusion: Functional violations of various organs and systems in catamnesis in persons who have had diphtheria have been revealed. The algorithm of medical examination for the purpose of regulation and correction of process of their adaptation has been offered.