Hi @robinll. With PV (Polycytmenia Vera) it is generally the red blood count that is elevated, though it can also involve over production of white cells and platelets. Quite often the cause behind this is an acquired mutation in one or more genes that control the production of cells such as the JAK2 gene. Polycythemia vera (PV) is one of a related group of blood cancers known as “myeloproliferative neoplasms” (MPNs) in which cells in the bone marrow that produce the blood cells don’t develop and function normally.
Because they are proliferative, that means these conditions can change over time. It is possible that there have been changes in your condition that requires more evaluation such as a bone marrow biopsy or genetic testing to see if you have mutations involved and the over all health of your bone marrow in its ability to make healthy cells.

Here’s a quick fact sheet from the Leukemia & Lymphoma Society that you might helpful: https://www.lls.org/sites/default/files/file_assets/FS13_PolycythemiaVera_FactSheet_final5.1.15.pdf#:~:text=In%20PV%2C%20red%20cells%2C%20white%20cells%20and%2C%20often%2C,is%20not%20a%20cause%20of%20any%20significant%20efects.

When you were diagnosed with PV did your hematologist check for genetic mutations?