Over the past year, my CBC results have shown elevated platelet, MCV and MCH levels. Platelet count varies from 442-485, MCV is 98.3 and MCH is 32.3. Occassionally, my WBC and GRAN will be high as well, but not consistently (this could be explained by a sinus infection I had at the time as well). My doctor says that he doesn't think further investigation is necessary, but after a year, I'm not so sure. I'm 37 years old, 4' 11" tall and weigh 115 lbs. What are the possible causes of fluctuating (but consistantly high) platelet, MCV and MCH levels?