An Overview of Secondary Polycythemia

An Overproduction of Red Blood Cells Caused by Health Disorders

Updated on January 15, 2023

Medically reviewed by Steffini Stalos, DO

Red blood cells, illustration — KTS Design / Science Photo Library / Getty Images

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.

Secondary Polycythemia Symptoms

Symptoms of secondary polycythemia, which are the same as those for primary polycythemia, 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

Causes

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:

Brain, liver, or uterine tumors
Chronic carbon monoxide exposure
Chronic heart disease
Chronic lung disease including chronic obstructive pulmonary disease (COPD)
Diuretics
Hypoventilation
High altitude
Kidney cysts
Obesity
Performance-enhancing drugs or blood doping in sports
Sleep apnea

Diagnosis

Measuring oxygen levels in the blood with a blood test known as arterial blood gas (ABG) can help healthcare providers 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, such as a chest X-ray, computed tomography (CT), or ultrasound, to detect the enlargement of the heart, liver, or spleen.

Your healthcare provider may also use a genetic test that looks for a mutation in a gene called JAK2 that affects the bone marrow and blood cells. This test is positive in most cases of primary polycythemia and, as a result, is used to differentiate between primary polycythemia and secondary polycythemia.

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 the time to treat the underlying condition, healthcare providers 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.

Coping

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 healthcare provider will guide you along the best path for resolving both.

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