Thanks. It's helpful to hear your experience. Did your platelets stay stable over time and then spike up or did they gradually increase over time?

The upper limit of the reference range for the Kaiser lab is 400, so mine are slightly over normal. The other thing I've discovered in reading research articles online is that regardless of whether they fall in the normal range, a platelet count of 400 is probably at least two standard deviations beyond the mean of the general population. In other words, 98% or more people have lower platelet counts. The average platelet count for women of my age is around 260. Platelets that much higher than average are associated with a variety of negative outcomes. It's just really hard to know what to do with this information and what tests to ask for. I am hopefully getting a referral to hematologist. I'm starting to think that the JAK2 testing might be a good idea. If JAK2 is positive, then at least I have a reason for the high platelets. If it's negative, then maybe I push harder for other cancer screenings.