How do you workup erythrocytosis with a normal or elevated serum erythropoietin?

First, I would consider using the term erythrocytosis rather than polycythemia. Too often, use of the term polycythemia may suggest polycythemia vera (PV) (a malignancy) rather than something more benign.

The recommended up front testing in the evaluation of erythrocytosis consists of up front JAK2V6...

When working up erythrocytosis and normal or elevated EPO level, I work up causes for secondary erythrocytosis based on H&P. This work up includes pulmonary evaluation to evaluate for hypoxia, obesity hypoventilation syndrome, OSA testing, review of tobacco use, carbon monoxide exposure, testosteron...