In this module, we will discuss the approach to a patient with elevated hemoglobin. The laboratory definition of polycythemia will be explained. You will gain an understanding of how to distinguish between elevated hemoglobin is due to plasma volume loss, a mutation in erythropoietin receptor or due to exogenous medication. Important aspects of history-taking will be discussed including immediately ruling out acute thrombotic or hemorrhagic events. Aspects of physical examination including investigative modalities will be discussed. In addition to referral to hematologist care, patients with polycythemia vera must be managed for cardiac risk factors.