What is Secondary Polycythemia?

There are two types of polycythemia: primary and secondary. Primary polycythaemia is genetic and most commonly a result of cell mutation in the bone marrow, where red blood cells are created. In secondary polycythemia, a pre-existing condition causes the body to overproduce red blood cells. People with secondary polycythemia typically have excess erythropoietin (EPO), a hormone that drives the formation of red blood cells. Though secondary polycythemia may have a genetic component, it does not cause a mutation in the bone marrow. Alternately, those with primary polycythemia don't have excess EPO.

Individuals with mild secondary polycythemia may not have any symptoms, while others may experience headaches, fatigue, stomach discomfort, dizziness, blurred vision, high blood pressure, and periods of confusion. Other symptoms of the condition include tingling or a "pins and needles" sensation in the feet, legs, hands, and arms, bleeding problems, such as bruising and nosebleeds, breathing difficulty, chest pain, ringing in the ears, and weakness and muscle pain. In some cases, people with secondary polycythemia also suffer from gout, which causes joint pain, swelling, and stiffness, and red, itchy skin, especially following a shower or bath.

Slow blood flow can result in blood clots, which put individuals at risk for life-threatening conditions such as pulmonary embolisms, heart attacks, and stroke. Deep vein thrombosis, blood clots in the legs that can move to other parts of the body, may also develop. Symptoms of deep vein thrombosis and pulmonary embolism include swelling, tenderness, pain, and redness in one leg, breathlessness, dizziness, coughing up blood, upper back or chest pain, and fainting.

A variety of conditions can lead to secondary polycythemia. Chronic obstructive pulmonary disease (COPD) and sleep apnea can cause overproduction of red blood cells due to the tissues receiving insufficient oxygen. Lung disease, Pickwickian syndrome, and obesity may also lead to the disease. Other causes of secondary polycythemia include carbon monoxide poisoning, performance-enhancing drugs, living at high altitudes, diuretics, and kidney cysts or disease. Parathyroid tumors, benign fibroids, adrenal gland tumors, certain brain tumors, kidney cancer, and liver cancer can also result in too much EPO.

Obesity, smoking, alcohol use, and high blood pressure are all risk factors for developing secondary polycythemia. A high red blood cell distribution width or anisocytosis, a wide variety in the red blood cells sizes within an individual's body, can also contribute to the disease.

A thorough medical history and investigation of symptoms will help a doctor determine whether a patient has secondary polycythemia. If she suspects the condition, she will order a blood test to measure red blood cell count and hematocrit levels, which indicates how much space the red blood cells take up in the blood. If someone has an excessive number of cells, the doctor may refer him to a hematologist, a doctor who specializes in diseases of the blood. A hematologist can help determine the underlying cause of the secondary polycythemia.

One treatment option for secondary polycythemia is venesection. It is the quickest and simplest way to decrease the number of red blood cells in the body. A doctor may recommend this treatment method if the patient is experiencing symptoms that suggest the blood is too thick, or has a history of blood clots. In venesection, a technician removes a pint of blood. Frequency depends on the patient, who may initially require weekly treatments, but with improvement may only need them ever few months or even every two or three years.

An essential part of managing secondary polycythemia is preventing dangerous blood clots. People with secondary polycythemia may take low doses of aspirin to thin the blood and help prevent blood clots. A physician may also prescribe other medications to address the symptoms of the condition.

Many people will also require treatment for the condition causing their secondary polycythemia. For instance, non-steroid anti-inflammatory drugs (NSAIDs) can manage gout, and bronchodilators or inhaled steroids can treat COPD. Lifestyle changes such as losing weight, stopping smoking, and managing high blood pressure can reduce the risk of life-threatening blood clots.

How much secondary polycythemia affects someone depends on the severity of the underlying condition. Provided the underlying cause is not serious, people with secondary polycythemia can live normal lives of average longevity. Anyone with the condition should learn the symptoms of blood clots so they can seek medical attention at the earliest sign.