Is Polycythemia a Cancer? Causes, Symptoms, Treatment

Medically Reviewed on 1/4/2022
Is Polycythemia a Cancer
Polycythemia can be caused by polycythemia vera, a type of blood cancer that results when bone marrow makes too many red blood cells

Polycythemia can be caused by polycythemia vera, a type of blood cancer that results when bone marrow makes too many red blood cells.

Polycythemia (also called polyglobulia) is a disease in which the hematocrit level (volume of red blood cells) and hemoglobin concentration are raised in the peripheral blood. This may be because of an increase in the number of red blood cells or a decrease in plasma volume. This causes blood thickening and slows blood flow, which can lead to serious problems. Treatment of polycythemia includes treating any underlying conditions, if possible, and bringing down blood cell levels.

  • Hematocrit (HCT): Polycythemia is considered when hematocrit levels are over 48% in women and 52% in men.
  • Hemoglobin (HGB): Polycythemia is considered when hemoglobin levels are over 16.5 grams/dL in women and 18.5 grams/dL in men.

What causes polycythemia?

Polycythemia is the result of increased demand for oxygen in the body. It occurs when hemoglobin cannot carry the required amount of oxygen from the lungs. There are two main causes of polycythemia, which determine each type.

  1. Primary polycythemia vera: Occurs due to a hereditary genetic mutation. Typically, all individuals diagnosed with polycythemia have a mutated JAK2 gene. In most cases, polycythemia is not innate (passed down through generations), yet it is genetic in a few cases. Changes in the TET2 gene are also found in polycythemia cells.
  2. Secondary polycythemia (acquired): Occurs in individuals with low degrees of oxygen in their blood for extensive stretches of time. The lack of oxygen for longer durations causes the body to produce higher amounts of erythropoietin, which is a hormone produced by the kidneys that signal the bone marrow cells to produce red blood cells. An excessive amount of erythropoietin in the body can result in the production of a large number of red blood cells due to any underlying acquired cause.

Chronic pulmonary disease (e.g., emphysema, which is abnormal distension of the lungs with air) and extreme obesity (which may severely impair pulmonary ventilation) result in absolute polycythemia (Pickwickian syndrome). Congenital heart disorders, enzymatic or hemoglobin abnormality, excessive use of coal tar derivatives, and tumors can also cause polycythemia.


Anemia: Common Causes, Symptoms, Types, and Treatment See Slideshow

What are different types of polycythemia?

Polycythemia is further subdivided into categories:

  • Relative: Occurs post blood volume loss in the body.
  • Transient: When many red blood cells unexpectedly enter circulation from storage.
  • Absolute: Increase in the actual mass of red blood cells in the body.

Relative polycythemia may be the result of abnormally high fluid intake or excessive loss of body fluid, for example, severe vomiting, diarrhea, or non-stop sweating. Relative and transient polycythemia go away when the underlying condition that has caused it is treated. Absolute polycythemia, however, is when the exact cause is known and is called erythrocytosis.

In rare cases, neonatal polycythemia may occur due to the transfusion of placental blood to the baby or chronic oxygen insufficiency of the fetus (intrauterine hypoxia) due to placental inadequacy.

What are the signs and symptoms of polycythemia?

Symptoms of polycythemia occur gradually over time. The condition may be diagnosed during a normal blood examination or when examining another condition. Symptoms may include:

Patients with polycythemia may have other blood disorders as well. Consequently, itching post-shower (post-bath pruritus) and joint pain may present as symptoms.

How is polycythemia diagnosed?

Polycythemia can be diagnosed through a blood test to check:

  • Number of red blood cells (red blood cell count)
  • How much space the red blood cells take up in the blood (hematocrit level)

A high concentration of red blood cells indicates polycythemia. To confirm the diagnosis and determine the underlying cause, more tests may be conducted:

  • Blood test to identify changes in the JAK2 gene
  • Ultrasound scan of the abdomen to identify problems in the kidneys

What are treatment options for polycythemia?

The goal of treatment for polycythemia is to reduce the volume of red blood cells to control symptoms and complications and treat any underlying causes.

  • Venesection (removing blood): Venesection is the quickest method to reduce the number of red blood cells in the blood. Venesection includes the removal of about 16.9 ounces (half a liter) of blood at a time. Initially, treatment may be required every week, but once polycythemia is under control, it may only be needed every 6-12 weeks or less.
  • Medications to help reduce red blood cells: Medication may be prescribed to slow down the production of red blood cells. A wide range of drugs are available, and the patient’s age, health, and red blood cell count should be taken under consideration when choosing the most appropriate treatment. Examples include:
    • Hydroxycarbamide: Administered daily
    • Interferon: Administered via infusion into the abdomen or thigh 1-3 times a week
  • Medications to prevent blood clots: Daily low-dose aspirin pills may be prescribed to help prevent blood clots and reduce the risk of other serious complications, such as coronary heart disease or cerebrovascular disease.
  • Radiation therapy: Occasionally, radiation therapy in the form of radioactive phosphorus may be necessary to restrain the overactivity of the bone marrow cells and help reduce the production of red blood cells.
  • Lifestyle changes: Making lifestyle changes can help reduce the risk of possibly serious complications for all types of polycythemias:

When to see a doctor for polycythemia

If left untreated, polycythemia can cause and increase the risk of serious issues, such as:

  • Pneumonic embolism, which is a blockage in the vein that carries blood from the heart to the lungs
  • Deep vein thrombosis (DVT), which is a blockage that forms in the veins in the legs
  • Heart attack and stroke

Seek medical assistance immediately if there are indications of DVT or a pulmonary embolism. Symptoms include:

  • Pain, swelling, redness, and tenderness in one of the legs
  • Heavy ache in the affected area
  • Warm skin around the clot
  • Breathlessness
  • Chest or upper back pain
  • Coughing up blood
  • Feeling lightheaded or dizzy
  • Fainting

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Medically Reviewed on 1/4/2022
Image Source:

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Nagalla S. Polycythemia Vera. Medscape.

Nabili SM. High Red Blood Cell Count (Polycythemia) Symptoms, Types, Causes, Diagnosis, Treatment, and Life Expectancy. MedicineNet.