What are the differential diagnoses of polycythemia vera?

1. Secondary polycythemia: This can be caused by conditions such as chronic hypoxia (e.g. chronic obstructive pulmonary disease), high altitude, or tumors that produce erythropoietin.

2. Essential thrombocythemia: This is a myeloproliferative disorder characterized by an elevated platelet count, and can sometimes be confused with polycythemia vera.

3. Chronic myeloid leukemia: This is a type of leukemia that can present with elevated red blood cell counts, similar to polycythemia vera.

4. Primary myelofibrosis: This is another myeloproliferative disorder that can present with symptoms similar to polycythemia vera, such as an enlarged spleen and abnormal blood counts.

5. Hereditary erythrocytosis: Some individuals may have a genetic predisposition to elevated red blood cell counts, which can mimic the symptoms of polycythemia vera.

6. Hypothyroidism: Low levels of thyroid hormone can sometimes lead to an increase in red blood cell production, causing symptoms similar to polycythemia vera.

7. Dehydration: Severe dehydration can lead to hemoconcentration and elevated red blood cell counts, which may be mistaken for polycythemia vera.

- Primary myelofibrosis
- Essential thrombocythemia
- Idiopathic erythrocytosis
- Polycythemia rubra vera
- Secondary polycythemia