BACKGROUND: Post-COVID syndrome ostcoid syndrome is a consequence of the multimodal systemic effect of the SARS-CoV-2 virus on the human body, and leads to a variety of clinical symptoms that require correction. In particular, there is an increase in the level of allostatic load and the risk of maladaptation. One of the means of effective non-drug effects on the separated consequences of COVID-19 is the use of hydrobalneotherapy methods as part of a rehabilitation course.
 AIM: To study the influence of various hydrobalneotherapy methods as part of comprehensive outpatient rehabilitation on the clinical-functional and psychoemotional status of patients with post-COVID syndrome.
 MATERIALS AND METHODS: 160 patients undergoing outpatient rehabilitation for manifestations of post-COVID syndrome, 74 men and 86 women, with a median age of 50 [43; 55.1] years, were comprehensively examined. Patients were randomized to 4 groups of 40, depending on the non-drug exposure method in the rehabilitation program: 1st group ― with the inclusion in the individual rehabilitation program of a course of chloride-sodium mineral baths in the amount of 10 procedures, 2nd group ― patients who were assigned a 10-day course of hot tubs, 3rd group ― 40 patients, along with exercise therapy, who underwent a 10-day course of general baths "Biolong", and 4th, control group of patients who did not undergo outpatient rehabilitation.
 RESULTS: The most frequent complaints were increased fatigue ― 88.8% of subjects, memory loss ― 46.9%, headache and dizziness ― 38.8%, dyspnea during physical activity ― 35.6%. The most frequent electrocardiogram parameters were sinus tachycardia (4.4%) and sinus bradycardia (8.1%). The mean allostatic load index of all patients was 3 [2; 3], which corresponds to the average allostatic overload. Against the background of rehabilitation measures with the inclusion of preformed physical factors, regression of the main complaints (weakness was detected in 24.2% of cases, memory decline ― in 20%, headache, dizziness ― in 17.5%, dyspnea ― in 15%, sleep disturbance ― in 10%, tachycardia and discomfort in the heart area ― in 7.5%) and improvement of electrocardiogram parameters were noted: sinus tachycardia and ventricular extrasystole were not noted, bradycardia was recorded in 2.5% of cases instead of 8.1%, repolarization process disorders ― in 2.5% instead of 8.1% before rehabilitation. In the group of patients who received whirlpool baths, improvement of external respiratory function parameters was noted: forced vital capacity of lungs increased by 12.1% (p 0.01), forced expiratory volume in the 1st second ― by 9.6% (р 0.05), the distance traveled according to the results of the test with 6-minute walking increased by 2.2% (р 0.05). In the group of those who received general baths with the preparation "Biolong", there was registered an increase in forced expiratory volume in the 1st second by 9.4% (р 0.05), an increase in the distance traveled during the 6-minute walk test by 8, 3% (р 0.05), decrease in norepinephrine level by 17.4% (р 0.05), adrenaline level by 13% (р 0.05) and cortisol level by 26.2% (р 0.01), glutathione peroxidase activity level by 13.6% (р 0.05). In the group of patients who received sodium chloride baths, there was a tendency to improvement of central hemodynamic parameters, reduction of adrenaline and noradrenaline parameters by 14.5% and 19.7% respectively (р 0.05). All rehabilitation groups showed a decrease in the Beck depression scale and Spielberger anxiety scale, K. Maslach questionnaire (emotional exhaustion and reduction of personal achievements), Bass–Perry aggression level questionnaire and Schulte table (mental stability), as well as a decrease in the level of allostatic load. In the control group, no dynamics of complaints and indicators was noted.
 CONCLUSION: In patients with post-COVID syndrome, a variety of complaints and a number of electrocardiogram disorders, clinical and functional parameters were identified. The study revealed positive dynamics against the background of the rehabilitation course with the inclusion of hydrobalneotherapy methods in the form of significant regression of complaints, clinical and functional disorders and changes in psychoemotional background and cognitive status. A decrease in allostatic load was noted after a course of non-drug rehabilitation.