Polycythemia vera is a serious, but very rare blood disorder in children. With polycythemia vera, the bone marrow makes too many red blood cells. The extra cells make the blood too thick. This may lead to blood clots. The clots can decrease the blood supply to organs, tissues, and cells.


An abnormal gene causes polycythemia vera. Although it is more common in some families, it is not  passed from parents to children.


Some children do not have symptoms and polycythemia vera may be found when they're having blood tests for other reasons. Symptoms occur more often in adults. 

Symptoms can occur a bit differently in each child. They can include:


  • Dizziness
  • Feeling weak and tired
  • Trouble breathing
  • Enlarged spleen
  • Trouble seeing
  • Itching or burning
  • Reddish coloring of face
  • Bleeding gums
  • Losing weight

The symptoms of polycythemia can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.


The healthcare provider will ask about your child’s symptoms and health history. He or she will give your child a physical exam. Your child may also have tests, such as:

  • Hemoglobin and hematocrit. It measures the amount of hemoglobin and red blood cells in the blood.
  • Complete blood count, or CBC. A complete blood count checks the red blood cells, white blood cells, blood clotting cells (platelets), and sometimes, young red blood cells (reticulocytes). It includes hemoglobin and hematocrit and more details about the red blood cells.
  • Peripheral smear. A small sample of blood is examined under a microscope. Blood cells are checked to see if they look normal or not.
  • Erythropoietin (EPO) level. This test measures the amount of EPO in the blood. EPO is a hormone involved in red blood cell production.


Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

Your child's health care provider will likely refer you to a hematologist, a specialist in blood disorders. Treatment may include:

  • Venipuncture or removing some blood, thus reducing the number of red blood cells (similar to a person donating blood)
  • Low-dose of aspirin to prevent blood clots
  • Medications to decrease the production of red blood cells in the bone marrow
  • Other treatments are being studied


Complications depend on how severe the polycythemia is. They include:

  • Blood clots in the veins of the liver
  • Deep vein thromboses or blood clots in the veins
  • Heavy bleeding
  • Stroke
  • Leukemia

Living with

Your child will be monitored for changes in blood test results or signs and symptoms of complications. Your child should avoid extreme heat, like hot baths. Heat may make some symptoms like itching and burning worse. And he or she should stay away from sports and activities that are likely to cause injuries. Injuries may increase the risk of bleeding.

When to Call a Healthcare Provider

Call your child's healthcare provider if you notice new or worsening symptoms. For example, call if you see that your child is more tired than usual. Call your child's healthcare provider or seek medical care if your child:

  • Is injured
  • Has pain in his or her arms or legs or abdomen (may be from a blood clot)

Key Points

  • Polycythemia vera is blood disorder in which the bone marrow produces too many red blood cells. The extra cells make the blood too thick, increasing the risk of blood clots.
  • Blood clots may cause serious problems depending on where they form. The clots can decrease the blood supply to the heart, brain, or liver, for example.
  • Treatment may include venipuncture to remove blood and taking aspirin.

Next Steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.