Stress is an element of each human's life and an indicator of its quality. Thermal mineral waters have been used empirically for the treatment of different diseases for centuries. Aim of the Study. To investigate the effects of highly mineralised geothermal water balneotherapy on distress and health risk. Methodology. A randomized controlled clinical trial was performed with 130 seafarers: 65 underwent 2 weeks of balneotherapy with 108 g/L full-mineralisation bath treatment; the others were in control group. The effect of distress was measured using the General Symptoms Distress Scale. Factorial and logistic regression analyses were used for statistical analysis. Results. A significant positive effect on distress (P < 0.001) was established after 2 weeks of treatment: the number of stress symptoms declined by 60%, while the intensity of stress symptoms reduced by 41%, and the control improved by 32%. Health risks caused by distress were reduced, and resources increased, whereas the probability of general health risk decreased by 18% (P = 0.01). Conclusion. Balneotherapy with highly mineralised geothermal water reduces distress, by reducing the health risk posed by distress by 26%, increasing the health resources by 11%, and reducing probability of general health risk by 18%. Balneotherapy is an effective preventive tool and can take a significant place in integrative medicine.