It can come from low iron. There are
also other causes, including blood
cancers - which is probably why
you were tested for CML.
Another cause is "essential thrombocytosis", which I think would be more associated with super high platelet counts. So we need to know your CBC results.
There is also the neutrophilia (I'm guessing you made a typo above and left out the "ia"). We need to know if you neutrophil count is normal high (as in an infection) or super high.