<Li> Iatrogenic - Secondary polycythemia can be induced directly by phlebotomy (blood letting) to withdraw some blood, concentrate the erythrocytes, and return them to the body . </Li> <Li> Genetic - Heritable causes of secondary polycythemia also exist and are associated with abnormalities in hemoglobin oxygen release . This includes patients who have a special form of hemoglobin known as Hb Chesapeake, which has a greater inherent affinity for oxygen than normal adult hemoglobin . This reduces oxygen delivery to the kidneys, causing increased erythropoietin production and a resultant polycythemia . Hemoglobin Kempsey also produces a similar clinical picture . These conditions are relatively uncommon . </Li> <P> Conditions where the secondary polycythemia is not as a result of physiologic adaptation and occurs irrespective of body needs include: </P> <Ul> <Li> Neoplasms - Renal - cell carcinoma or liver tumors, von Hippel - Lindau disease, and endocrine abnormalities including pheochromocytoma and adrenal adenoma with Cushing's syndrome . </Li> <Li> People whose testosterone levels are high because of the use of anabolic steroids, including athletes who abuse steroids, or people on testosterone replacement for hypogonadism or transgender hormone replacement therapy, as well as people who take erythropoietin, may develop secondary polycythemia . </Li> </Ul>

What's the difference between polycythemia and polycythemia vera