Polycythemia: Types, Causes, Symptoms, Treatment, Complications, Risk Factors, Prognosis
What is Polycythemia?
Polycythemia is a condition where the RBC count is high and the person has a high concentration of red blood cells in the blood. People with Polycythemia have thicker blood consistency, which makes it difficult for it to circulate around the body.
Symptoms of Polycythemia or What Happens if RBC Count is High?
This is what happens if the RBC count is high; if the polycythemia is mild, then it may not produce any symptoms in the patient. Common symptoms of polycythemia or high RBC count are:
- Blurry vision.
- Pain in the chest.
- Muscle pain.
- Ruddy complexion.
- Ringing in the ears (tinnitus).
If a person has developed polycythemia as a result of liver cancer, kidney cancer, or other erythropoietin-secreting tumors, then symptoms include weight loss, abdominal fullness or pain and jaundice.
Types of Polycythemia
Primary Polycythemia: In this type of polycythemia, the RBC count is high from intrinsic problems occurring in the production of RBCs.
Secondary Polycythemia: This type of polycythemia often occurs as a response to other underlying conditions or factors, which promote the production of red blood cells.
Polycythemia Rubra Vera: This is a rare medical condition where there is an abnormally high level of red blood cells usually along with leukocytosis (an increased white blood cell count) and thrombocytosis (increased platelet count). Clinical features of polycythemia Rubra Vera also include splenomegaly (spleen enlargement) and low erythropoietin levels.
Primary Familial and Congenital Polycythemia (PFCP): Genetic mutations is also thought to cause primary familial and congenital polycythemia (PFCP) which results in increased responsiveness to normal levels of erythropoietin. Different mutations to the EPOR gene are responsible for causing most of the cases.
Relative Polycythemia: In some types of secondary polycythemia, the RBC count is perceived to be excessively high because of an increased concentration of blood. This can occur from plasma volume loss from dehydration, diarrhea, severe vomiting or excessive sweating. In such cases, polycythemia is referred to as relative polycythemia, as the actual count of RBC is not abnormal.
Smoker's Polycythemia: In this condition, there are increased levels of deoxygenated hemoglobin resulting in an increased RBC count.
Stress Polycythemia: The term "stress polycythemia" is used if there is a chronic state of low plasma volume, which is commonly seen in hardworking, active, anxious, middle-aged individuals. Such individuals will have normal RBC volume, but low plasma volume. Stress polycythemia is also known as pseudopolycythaemia, stress erythrocytosis and Gaisbock's disease.
Chuvash Polycythemia: This is a rare genetic condition where there is increased activity of the gene, which is responsible for production of erythropoietin.
Causes of Primary Polycythemia
The causes of primary polycythemia include inherited or acquired genetic mutations, which cause abnormally increased levels of red blood cell precursors. Primary congenital and familial polycythemia and polycythemia Rubra Vera come under this category.
Causes of Secondary Polycythemia
The cause of secondary polycythemia is often increased production of erythropoietin (EPO) as a response to chronic hypoxia or from an erythropoietin-secreting tumor. Individuals who live in high altitudes can also develop polycythemia where the RBC production and count becomes high in order to compensate for the low oxygen levels in the atmosphere and inadequate tissue oxygenation.
Risk Factors for Polycythemia
- Smoking is a significant risk factor for polycythemia.
- Hypoxia occurring from chronic lung disease is also a major risk factor for polycythemia.
- Chronic carbon monoxide exposure.
- High altitudes.
Diagnosis of Polycythemia
Blood tests help in diagnosing Polycythemia. To determine the cause of polycythemia, medical history and physical examination of the patient are conducted. Questions which are asked of the patient include about the patient's smoking history, breathing problems, whether the patient lives at high altitudes for long periods, chronic cough or sleep disturbances. It is also important to find out if the patient previously had a diagnosis of heart disease, lung disease, liver or kidney cancer and clotting or bleeding problems.
Physical examination consists of assessment of patient's stature, oxygen saturation, vital signs, heart and lung exam and evaluation of enlarged spleen. Evidence of a chronic hypoxia is an important indication in patients with polycythemia. Signs of chronic hypoxia include cyanosis, pursed lip breathing or clubbing of the fingers. Redness of the soles and palms can also indicate polycythemia.
Other investigations, such as chest x-ray, echocardiogram and electrocardiogram (ECG) are done for screening heart disease or lung disease. Analysis of Hemoglobin is also needed. Blood tests can be done to rule out carbon monoxide poisoning.
Erythropoietin (EPO) levels in the blood are also helpful in finding the cause of polycythemia.
Treatment for Polycythemia
Treatment for polycythemia depends on its cause. Some of the treatment options for polycythemia consist of:
Venesection (blood-letting), where a volume (around half-liter) of blood is removed to rapidly reduce the number of RBCs in the blood. The quantity of blood removed and its frequency differs from patient to patient.
Medications such as interferon and hydroxycarbamide can be prescribed to decrease the production of RBCs. Low-dose aspirin can be given daily to prevent blood clots.
Lifestyle changes as quitting smoking and exercising regularly are strongly recommended. Underlying conditions which are causing polycythemia should be treated.
Complications of Polycythemia
Some of the potential complication of polycythemia is increased levels of RBCs circulating in the body which causes increased viscosity or thickness of the blood. This in turn increases the risk of deep vein thrombosis (DVT) or clots leading to heart attacks, strokes, pulmonary embolism and even death.
Polycythemia Rubra Vera can potentially transform into a blood cancer, haemorrhage or clotting problems.
Prevention of Polycythemia
Cutting down on risk factors of Polycythemia or increased count of RBC, such as chronic smoking, carbon monoxide exposure, which can cause Polycythemia help in preventing it. Reducing risk factors for heart problems by controlling hypertension and diabetes mellitus can potentially help in preventing polycythemia. However, primary and congenital polycythemia disorders are not preventable.
Prognosis of Polycythemia
Prognosis of polycythemia depends on the underlying cause. If proper treatment is started and the patient does not have any other complications or medical conditions then the prognosis is good and the life expectancy of the patient need not be affected by polycythemia.