Polycythemia vera (NORD)


00:00 / 00:00



Polycythemia vera (NORD)

Hematological system


Iron deficiency anemia



Sideroblastic anemia

Anemia of chronic disease

Lead poisoning

Hemolytic disease of the newborn

Glucose-6-phosphate dehydrogenase (G6PD) deficiency

Autoimmune hemolytic anemia

Pyruvate kinase deficiency

Paroxysmal nocturnal hemoglobinuria

Sickle cell disease (NORD)

Hereditary spherocytosis

Anemia of chronic disease

Aplastic anemia

Fanconi anemia

Megaloblastic anemia

Folate (Vitamin B9) deficiency

Vitamin B12 deficiency

Fanconi anemia

Diamond-Blackfan anemia

Heme synthesis disorders

Acute intermittent porphyria

Porphyria cutanea tarda

Lead poisoning

Coagulation disorders


Vitamin K deficiency

Platelet disorders

Bernard-Soulier syndrome

Glanzmann's thrombasthenia

Hemolytic-uremic syndrome

Immune thrombocytopenic purpura

Thrombotic thrombocytopenic purpura

Mixed platelet and coagulation disorders

Von Willebrand disease

Disseminated intravascular coagulation

Heparin-induced thrombocytopenia

Thrombosis syndromes (hypercoagulability)

Antithrombin III deficiency

Factor V Leiden

Protein C deficiency

Protein S deficiency

Antiphospholipid syndrome


Hodgkin lymphoma

Non-Hodgkin lymphoma


Chronic leukemia

Acute leukemia

Leukemoid reaction

Leukemoid reaction

Dysplastic and proliferative disorders

Myelodysplastic syndromes

Polycythemia vera (NORD)

Myelofibrosis (NORD)

Essential thrombocythemia (NORD)

Langerhans cell histiocytosis

Mastocytosis (NORD)

Plasma cell dyscrasias

Multiple myeloma

Monoclonal gammopathy of undetermined significance

Waldenstrom macroglobulinemia

Hematological system pathology review

Microcytic anemia: Pathology review

Non-hemolytic normocytic anemia: Pathology review

Intrinsic hemolytic normocytic anemia: Pathology review

Extrinsic hemolytic normocytic anemia: Pathology review

Macrocytic anemia: Pathology review

Heme synthesis disorders: Pathology review

Coagulation disorders: Pathology review

Platelet disorders: Pathology review

Mixed platelet and coagulation disorders: Pathology review

Thrombosis syndromes (hypercoagulability): Pathology review

Lymphomas: Pathology review

Leukemias: Pathology review

Plasma cell disorders: Pathology review

Myeloproliferative disorders: Pathology review


Polycythemia vera (NORD)


0 / 11 complete

USMLE® Step 1 questions

0 / 3 complete

High Yield Notes

10 pages


Polycythemia vera (NORD)

of complete


USMLE® Step 1 style questions USMLE

of complete

A 58-year-old female comes to her outpatient provider’s office for symptoms of fatigue, headaches, and pruritus that is worse with showering. The symptoms began three months ago. The patient consumes half-a-pack of cigarettes per day, has a 30-pack-year smoking history, and drinks 3-4 beers per week. Her temperature is 37.0°C (98.6°F), blood pressure is 120/73 mmHg, pulse is 71/min, and respiratory rate is 14/min. On physical exam, the patient is observed to have a reddish face. Cardiac and pulmonary exams are non-contributory. Abdominal examination reveals an enlarged spleen. Laboratory testing is ordered and the results are as follows:  
 Laboratory value  Result 
 Hemoglobin  19.0 g/dL 
 Hematocrit  57% 
 Erythrocytes  7.2 million/mm3 
 Leukocytes  12,900/mm3 
 Platelets  440,000/mm3 

Which of the following additional sets of findings would be expected in this patient? 

External References

First Aid








Aspirin p. 499

polycythemia vera p. 441


polycythemia vera p. 441

Hydroxyurea p. 448

polycythemia vera p. 441


Content Reviewers

Rishi Desai, MD, MPH


Evan Debevec-McKenney

Stefan Stoisavljevic, MD

In polycythemia vera, there are increased blood cell levels due to overproduction by the bone marrow, which is a soft tissue found within the bones.

Normally, about 45% of the total blood volume is made up of erythrocytes, or red blood cells, and their main function is to carry oxygen to tissues and bring carbon dioxide to the lungs so it can be expired. This value is called the hematocrit.

In polycythemia vera there’s an increase in red blood cell production.

It typically begins with a mutation in a single hematopoietic stem cell, which gives rise to red blood cells, white blood cells, and platelets.

In 90 percent of the affected individuals there is a mutation of the Janus Kinase 2 or JAK2 gene.

Normally, the kidneys produce erythropoietin which is a hormone that binds to receptors on the hematopoietic stem cells and activates JAK2 gene.

When that happens, it causes the cell to divide and thus produce more blood cells.

However, when there’s a mutation, it keeps JAK2 gene activated, and these cells are able to divide even in the absence of erythropoietin.

The mutated cells proliferate, and rapidly become the predominant hematopoietic cells in the bone marrow.

In time these cells start to die out and that’s when scar tissue forms.

At that point, the bone marrow can no longer produce blood cells, leading to anemia or low red blood cell levels, thrombocytopenia or low platelet levels, and leukopenia or low white blood cell levels. This is known as the spent phase.

And once the disease is in the spent phase, it’s really a different disease altogether - at that point it’s myelofibrosis.

The most common symptoms of polycythemia vera are fatigue, dizziness, increased sweating, redness in the face, blurred vision, and itchy skin especially after a hot shower.

Itchiness develops due to the increased number of basophils and mast cells which contain histamine that causes itching when released.


Polycythemia vera is a bone marrow disorder in which there is an overproduction of blood cells, often caused by a JAK2 mutation within hematopoietic cells in the bone marrow. It can lead to elevated hemoglobin and hematocrit and predispose an individual to develop blood clots. Symptoms may include fatigue, weakness, headaches, dizziness, itching, and abdominal pain. Treatment may include medications to lower blood cell formation, and prevention of blood clots, phlebotomy, and radiation therapy.


Copyright © 2023 Elsevier, except certain content provided by third parties

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.