Secondary vs. Primary Polycythemia: What's the Difference?

Red blood cells, artwork
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Similar to primary polycythemia vera, secondary polycythemia is a disorder that causes an over-production of red blood cells. When too many red blood cells are produced, the blood becomes thick, hindering its passage through the smaller blood vessels.

The difference between the two has to do with what the disorder is associated with. Secondary polycythemia is associated with an underlying disease process (such as COPD), but primary polycythemia is not.

Causes of Secondary Polycythemia  

Because secondary polycythemia is associated with an underlying disease process, factors that affect the red blood cells are usually a cause. The job of a red blood cell is to deliver oxygen to the body tissues. Smoking, for example, interferes with this process, so it is a common cause of secondary polycythemia. Others include:

  • Chronic carbon monoxide exposure
  • Chronic heart or lung disease (like COPD)
  • High altitude
  • Cysts of the kidneys
  • Brain, liver or uterine tumors

Symptoms of Secondary Polycythemia  

Symptoms of polycythemia include the following:

  • Weakness
  • Headache
  • Fatigue
  • Lightheadedness
  • Shortness of breath
  • Visual disturbances
  • Pruritis (itching)
  • Pain in the chest or leg muscles
  • Ruddy complexion
  • Confusion
  • Ringing in the ears (tinnitus)
  • Burning of the hands or feet

Diagnosis

Measuring oxygen levels in the blood with a blood test known as arterial blood gases (ABG's), can help doctors formulate a diagnose of secondary polycythemia.

Other blood tests include measurement of erythropoietin and red blood cell mass levels.

Additional diagnostic tests may include:

Treatment

Treatment for secondary polycythemia should control or eliminate the underlying condition.

Symptom relief may include medications such as antihistamines to relieve itching, or aspirin to soothe pain and burning associated with the disorder.

Because it takes time to treat the underlying condition, doctors sometimes use phlebotomy (bloodletting) in an attempt to reduce the number of red blood cells in the blood. As much as a pint may be withdrawn in one setting, as long as the patient can tolerate it.

Prognosis

If you're already coping with one condition that can cause secondary polycythemia, such as COPD or a tumor, learning that you have a second diagnosis to cope with is understandably frustrating. You want to feel better, not worse.

Remember that secondary polycythemia is caused by an underlying condition, most of which are well-known and have multiple treatment options available. Once the underlying cause is corrected, symptoms of the secondary polycythemia usually go away. Your health care provider will guide you along the best path for resolving both.

Source:

Smeltzer, S., Bare, Brenda. Brunner and Suddarth's Textbook of Medical-Surgical Nursing. Eight Edition. 1996. Lippincott-Raven Publishers.

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