An Overview of Secondary Polycythemia

Secondary polycythemia, similar to primary polycythemia vera, is a disorder that causes an overproduction 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, but primary polycythemia is not.

Symptoms of secondary polycythemia are the same as those for primary polycythemia and may include:

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

Primary polycythemia is caused by an abnormality of the cells In the bone marrow that form red blood cells. Secondary polycythemia is caused by a disorder originating outside of the bone marrow that causes overstimulation of the normal bone marrow, leading to an overproduction of red blood cells.

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 heart disease
• Chronic lung disease (including COPD)
• Sleep apnea
• Obesity
• Hypoventilation
• High altitude
• Kidney cysts
• Brain, liver, or uterine tumors
• Chronic carbon monoxide exposure
• Diuretics
• Performance-enhancing drugs

Measuring oxygen levels in the blood with a blood test known as arterial blood gasses (ABG) 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 include an electrocardiogram (ECG) to measure heart function and imaging tests, like a chest X-ray, computed tomography (CT), or ultrasound, to detect the enlargement of the heart, liver, or spleen.

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 the time to treat the underlying condition, doctors sometimes use phlebotomy (blood-letting) to reduce the number of red blood cells in plasma. As much as a pint (475 milliliters) may be taken in one sitting as long as the individual can tolerate it.

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 secondary polycythemia usually go away. Your health care provider will guide you along the best path for resolving both.