Increased hematocrit leads to increased turbulent flow of the blood due to the increased viscosity. Thrombus formation (blood clots) occurs preferentially in areas of turbulent flow. Do I think your small elevation of RBCs is a major risk factor for thromboembolic stroke? No. Do I think it is a factor when taken together with all your other risk factors (DIABETES is huge)? Could very well be. There's a lot of other things to consider in this situation. Do you have high BP, do you smoke, hows your cholesterol, how old are you, etc... For someone on this board to tell you to ignore your doc without knowing your whole history is rediculous.