You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is 1925. Causes of secondary polycythemia may include and explain in detail?
Secondary polycythaemia occur due to high altitude,cardiovascular disease ,pulmonary disease with alveolar hypoventilation,heavy smoking,inappropriate erythropoietin(renal cell carcinoma ,hydronephrosis,hepatocellular carcinoma ,cerebellar hemangioblastoma ,massive uterine leiomyoma.). Reference :Harsh mohan textbook of pathology sixth edition pg no 359.