Divided into primary and secondary causes based on underlying genetic mutations and other factors(refer to classification).

Common causes of polycythemia may include:

• Primary erythrocytosis^[1][2]

Polycythemia vera

• Secondary erythrocytosis

Congenital

• Erythropoietin receptor-mediated
• High oxygen affinity hemoglobin^[3]
• Bisphosphoglycerate mutase deficiency^[4]
• VHL(Von Hippel-Lindau) gene mutation (Chuvash erythrocytosis)^[5][6][7]
• PHD2 mutations
• HIF-2 alpha mutations^[8][9]

Acquired

• Hypoxia driven
  • Central hypoxic process:
    • Chronic Lung disease
    • Right-to-left cardiopulmonary vascular shunts
    • Carbon monoxide poisoning
    • Smoker’s erythrocytosis
    • Hypoventilation syndromes including sleep apnea (high-altitude habitat)
• Local renal hypoxia:
  • Renal Artery Stenosis
  • End-Stage Renal Disease
  • Hydronephrosis
  • Renal cysts (polycystic kidney disease)
  • Postrenal transplant erythrocytosis

Pathologic EPO production:^[10]

• Tumors
  • Cerebellar hemangioblastoma
  • Meningioma
  • Parathyroid carcinoma/adenomas
  • Hepatocellular carcinoma
  • Renal cell cancer
  • Pheochromocytoma
  • Uterine leiomyomas

Exogenous EPO:

• Drug associated
  • EPO administration
  • Androgen administration^[11]

Idiopathic erythrocytosis ^{[12][13] [14]}