Is an elevated blood platelet count over many years a reason for concern if no other blood count problem?

Yes.: You may have underlying blood disorder. It is best to talk to your doctor to begin investigation. Sometimes a hematologist may need to be involve if etiology can not be readily found.

Possibly: Essential thrombocytosis (high platelet count) is associated with increase risk of excessive clotting. The problem is worse if you become dehydrated. I had a patient who actually had a stroke attributed to essential thrombocytosis at age 41. Check in with your doctor soon.