The effect of thermal bathing upon platelet function was examined in clinically. Platelet number, adhesiveness and aggregation were examined in the 10 patients before and after a single bathing for 10 minutes, 41-43℃ in temperature. The diseases of the patients were external pile, duodenal ulcer, benign sigmoid colon polyp, etc. The specific diseases which interact the platelet function such as blood diseases and arterial occlusive diseases were not included. Antithrombogenic drugs were not used in any patients. The results of this study were summarized as follows. 1. Platelet number did not showd systemical
alteration by the bathing. 2. Both platelet adhesiveness and aggregation were changed to the lower degree after the bathing except a few cases. From these results, it was clarified that the thermal bathing was effective to control the platelet function and also effective in clinically to the prevention, therapy and rehabilitation of arterial occlusive diseases of heart, brain and the extremities.