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How Long Can You Have Polycythemia Vera Without Knowing?

Feb 9, 2026

Key takeaways

  • PV can go unnoticed for months to years because early symptoms may be mild, nonspecific, or absent, and many cases are found incidentally on routine blood tests. [1][2]
  • Persistently elevated hemoglobin/hematocrit often prompts clinician evaluation, which may include JAK2 mutation testing as part of confirming PV and distinguishing it from other causes of high counts. [3]
  • Once PV is confirmed, appropriate monitoring and treatment strategies (including hematocrit control) are used to lower the risk of blood clots over time. [4][5]

Overview

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm in which the bone marrow makes too many red blood cells. This can raise hematocrit and blood viscosity and is associated with an increased risk of thrombosis and other complications. [4][5] PV is often a slowly evolving myeloproliferative neoplasm; some patients are asymptomatic and are identified incidentally on routine blood counts, and patient-reported data suggest symptoms may precede diagnosis by a year or more—factors that can contribute to delayed recognition. [6][7][8]

How long can you have polycythemia vera without knowing?

PV can remain unrecognized for months to years, particularly when symptoms are mild or nonspecific; in the international MPN Landmark survey, PV respondents reported symptom duration before diagnosis of <6 months (25%), 6–12 months (23%), 1–2 years (21%), and >2 years (31%). [1] Early features (e.g., fatigue, microvascular symptoms, pruritus) can overlap with common conditions, and some patients are asymptomatic and identified incidentally after a full blood count. [2][9] Consistent with this, in the US REVEAL cohort, 89.7% of patients were diagnosed after an abnormal blood test, so PV is often first flagged when a CBC shows persistently elevated hemoglobin/hematocrit that prompts further clinical evaluation. [10]

Why does PV often go unnoticed?

PV can be subtle early on. Some people have few or no symptoms at diagnosis, and symptom burden varies widely between individuals. [11] In addition, elevated hemoglobin/hematocrit can also occur with other, more common explanations (for example, conditions associated with chronic low oxygen levels or reduced plasma volume), so clinicians typically evaluate the full clinical picture rather than relying on a single lab value. [3][5]

The role of routine testing and awareness

A CBC is often the first clue. If hemoglobin or hematocrit is persistently elevated, clinicians may order additional tests—commonly including JAK2 mutation testing—as part of confirming PV and distinguishing it from other causes of erythrocytosis. [3][12] If PV is diagnosed, management commonly focuses on lowering thrombotic risk, including maintaining hematocrit targets used in major evidence and guidance. [4][5]

Living with an early or asymptomatic diagnosis

An “early” diagnosis (sometimes before noticeable symptoms) can feel surprising, but it can be clinically helpful because it allows structured follow-up and risk-based management. In PV, maintaining hematocrit control is associated with fewer cardiovascular deaths and major thrombotic events in randomized evidence. [4][13] Ongoing follow-up with a hematology team also supports monitoring for disease evolution and addressing symptoms and cardiovascular risk factors over time. [5][14]

Final thoughts

PV can be silent for a long time, which is one reason routine blood testing sometimes uncovers it unexpectedly. If you’ve had persistent elevations in hemoglobin or hematocrit, or symptoms like unexplained headaches, dizziness, or post-shower itching, talk with your clinician about evaluation, including possible JAK2 testing. When PV is confirmed, early follow-up and evidence-based management help reduce long-term risks. [4][5]

Frequently asked questions (FAQs)

1. Can polycythemia vera exist without symptoms?

Yes, Some people are asymptomatic and are identified incidentally through a routine CBC. [2][15]


2. What early signs should I watch for?

Common early clues include fatigue, headaches, dizziness, blurry vision, and itching after warm showers. These are nonspecific and don’t always prompt immediate testing. [2]


3. How long can PV go undiagnosed?

It can be months to years, particularly when symptoms are mild/absent or routine labs are infrequent. [16]


4. Which tests help confirm PV?

A CBC showing persistently elevated hemoglobin/hematocrit raises suspicion. JAK2 mutation testing is commonly used as part of confirming PV in the appropriate clinical context. [2][3]


5. Does early diagnosis change outcomes?

Early recognition enables timely monitoring and management. In PV, maintaining hematocrit <45% is associated with lower rates of cardiovascular death and major thrombosis in randomized evidence. [4]


Abbreviation

  • PV — Polycythemia vera
  • MPN — Myeloproliferative neoplasm
  • MPNs — Myeloproliferative neoplasms
  • JAK2 — Janus kinase 2
  • CBC — Complete blood count
  • US — United States
  • FAQs — Frequently asked questions

References

  1. Harrison, C. N., Koschmieder, S., Foltz, L., Guglielmelli, P., Flindt, T., Koehler, M., et al. (2017). The impact of myeloproliferative neoplasms (MPNs) on patient quality of life and productivity: Results from the international MPN Landmark survey. Annals of Hematology, 96(10), 1653–1665. https://doi.org/10.1007/s00277-017-3082-y
  2. Stuart, B. J., & Viera, A. J. (2004). Polycythemia vera. American Family Physician, 69(9), 2139–2144. https://www.aafp.org/pubs/afp/issues/2004/0501/p2139.html
  3. Thiele, J., Kvasnicka, H. M., Gianelli, U., Arber, D. A., Tefferi, A., Vannucchi, A. M., Barbui, T., & Orazi, A. (2025). Evolution of WHO diagnostic criteria in "Classical Myeloproliferative Neoplasms" compared with the International Consensus Classification. Blood cancer journal, 15(1), 31. https://doi.org/10.1038/s41408-025-01235-7
  4. Marchioli, R., Finazzi, G., Specchia, G., Cacciola, R., Cavazzina, R., Cilloni, D., et al. (2013). Cardiovascular events and intensity of treatment in polycythemia vera. The New England Journal of Medicine, 368(1), 22–33. https://pubmed.ncbi.nlm.nih.gov/23216616/
  5. Tefferi, A., & Barbui, T. (2023). Polycythemia vera: 2024 update on diagnosis, risk-stratification, and management. American journal of hematology, 98(9), 1465–1487. https://doi.org/10.1002/ajh.27002
  6. Tefferi, A., Vannucchi, A. M., & Barbui, T. (2021). Polycythemia vera: historical oversights, diagnostic details, and therapeutic views. Leukemia, 35(12), 3339–3351. https://doi.org/10.1038/s41375-021-01401-3
  7. McMullin, M. F., Harrison, C. N., Ali, S., Cargo, C., Chen, F., Ewing, J., et al. (2019). A guideline for the diagnosis and management of polycythaemia vera: A British Society for Haematology Guideline. British Journal of Haematology, 184, 176–191. https://doi.org/10.1111/bjh.15648
  8. Grunwald, M. R., Stein, B. L., Boccia, R. V., Oh, S. T., Paranagama, D., Parasuraman, S., Colucci, P., & Mesa, R. (2018). Clinical and disease characteristics from REVEAL at time of enrollment (baseline): Prospective observational study of patients with polycythemia vera in the United States. Clinical Lymphoma Myeloma and Leukemia, 18(12), 788–795.e2. https://doi.org/10.1016/j.clml.2018.08.009
  9. BSH Committee. (2018). A guideline for the diagnosis and management of polycythaemia vera: A British Society for Haematology Guideline (Peer reviewed version). British Journal of Haematology. https://doi.org/10.1111/bjh.15648 https://pureadmin.qub.ac.uk/ws/files/162118293/PV_Guideline_revision_accepted_changes_2018.pdf
  10. Grunwald, M. R., Stein, B. L., Boccia, R. V., Oh, S. T., Paranagama, D., Parasuraman, S., Colucci, P., & Mesa, R. (2018). Clinical and disease characteristics from REVEAL at time of enrollment (baseline): Prospective observational study of patients with polycythemia vera in the United States. Clinical Lymphoma Myeloma and Leukemia, 18(12), 788–795.e2. https://doi.org/10.1016/j.clml.2018.08.009 https://pmc.ncbi.nlm.nih.gov/articles/PMC8148982/
  11. Grunwald, M. R., Burke, J. M., Kuter, D. J., Gerds, A. T., Stein, B., Walshauser, M. A., et al. (2019). Symptom burden and blood counts in patients with polycythemia vera in the United States: An analysis from the REVEAL study. Clinical Lymphoma Myeloma and Leukemia, 19(9), 579–584.e1. https://doi.org/10.1016/j.clml.2019.06.001
  12. Dentali, F., Squizzato, A., Brivio, L., Appio, L., Campiotti, L., Crowther, M., Grandi, A. M., & Ageno, W. (2009). JAK2V617F mutation for the early diagnosis of Ph- myeloproliferative neoplasms in patients with venous thromboembolism: a meta-analysis. Blood, 113(22), 5617–5623. https://doi.org/10.1182/blood-2008-12-196014
  13. Marchioli, R., Finazzi, G., Specchia, G., Cacciola, R., Cavazzina, R., Cilloni, D., et al. (2013). Cardiovascular events and intensity of treatment in polycythemia vera. The New England Journal of Medicine, 368(1), 22–33. https://doi.org/10.1056/NEJMoa1208500 https://www.nejm.org/doi/full/10.1056/NEJMoa1208500
  14. Marchetti, M., et al. (2022). Appropriate management of polycythaemia vera with cytoreductive drug therapy: European LeukemiaNet 2021 recommendations. The Lancet Haematology, 9(4), e301–e311. https://doi.org/10.1016/S2352-3026(22)00046-1
  15. Bagnall, B., Woodley, C., Bains, R., Gibson, K., Nawaz, A., Ryan, J., & McMullin, M. F. (2025). Exploring perceptions in the management and treatment of polycythaemia vera in the UK. Annals of hematology, 104(3), 1623–1631. https://doi.org/10.1007/s00277-025-06352-8
  16. Mesa, R., Miller, C. B., Thyne, M., Mangan, J., Goldberger, S., Fazal, S., Ma, X., Wilson, W., Paranagama, D. C., Dubinski, D. G., Boyle, J., & Mascarenhas, J. O. (2016). Myeloproliferative neoplasms (MPNs) have a significant impact on patients' overall health and productivity: the MPN Landmark survey. BMC cancer, 16, 167. https://doi.org/10.1186/s12885-016-2208-2