 [ Symptoms ] what causes a high white blood cell count & a high platelet count [ Disease ] because of the high number of possible conditions that could cause these blood test results it is impossible to tell you in a forum like this exactly what the cause is i suggest you consult the health care provider who ordered the test for an explanation your personal medical history plays a big role in interpreting any test results and your primary health care provider is in the best position to tell you what these results mean for you take care