Polycythemia corresponds to an increase in the amount of red blood cells, also called red blood cells or erythrocytes, in the blood, that is, above 5.4 million red blood cells per µL of blood in women and above 5.9 million red blood cells per µL of blood in men.
Due to the increase in the number of red blood cells, the blood becomes more viscous, which makes the blood circulate more difficultly through the vessels, which can cause some symptoms, such as headache, dizziness and even a heart attack.
Polycythemia can be treated not only to reduce the amount of red blood cells and blood viscosity, but also with the aim of relieving symptoms and preventing complications, such as stroke and pulmonary embolism.
Polycythemia symptoms
Polycythemia usually does not generate symptoms, especially if the increase in the number of red blood cells is not so great, being noticed only through the blood test. However, in some cases, the person may experience constant headache, blurred vision, red skin, excessive tiredness and itchy skin, especially after bathing, which may indicate polycythemia.
It is important that the person makes the blood count regularly and, if any symptoms related to polycythemia arise, go immediately to the doctor, because the increase in blood viscosity due to the increase in the number of red blood cells increases the risk of stroke, acute myocardial infarction. myocardium and pulmonary embolism, for example.
How the diagnosis is made
The diagnosis of polycythemia is made from the result of the blood count, in which it is noticed not only the increase in the number of red blood cells, but also an increase in the values of hematocrit and hemoglobin. See what the blood count reference values are.
According to the analysis of the blood count and the result of other tests performed by the person, polycythemia can be classified into:
- Primary polycythemia, also called polycythemia vera, which is a genetic disease characterized by the abnormal production of blood cells. Understand more about polycythemia vera; Relative polycythemia, which is characterized by an increase in the number of red blood cells due to a decrease in plasma volume, as in the case of dehydration, for example, not necessarily indicating that there was a greater production of red blood cells; Secondary polycythemia, which occurs due to diseases that can lead to an increase not only in the number of red blood cells, but also in other laboratory parameters.
It is important to identify the cause of polycythemia in order to establish the best type of treatment, avoiding the appearance of other symptoms or complications.
Main causes of polycythemia
In the case of primary polycythemia, or polycythemia vera, the cause of the increase in the production of red blood cells is a genetic alteration that causes deregulation in the production process of red cells, leading to an increase in red blood cells and, sometimes, leukocytes and platelets.
As for relative polycythemia, the main cause is dehydration, as in these cases there is loss of body fluids, leading to an apparent increase in the number of red blood cells. Normally in the case of relative polycythemia, the levels of erythropoietin, which is the hormone responsible for regulating the red blood cell production process, are normal.
Secondary polycythemia can be caused by several situations that can lead to an increase in the number of red blood cells, such as cardiovascular diseases, respiratory diseases, obesity, smoking, Cushing's syndrome, liver diseases, early-stage chronic myeloid leukemia, lymphoma, renal disorders and tuberculosis. In addition, the number of red blood cells may increase due to prolonged use of corticosteroids, vitamin B12 supplements and medications used to treat breast cancer, for example.
How to treat
The treatment of polycythemia should be guided by a hematologist, in the case of the adult, or by a pediatrician in the case of the baby and child, and depends on the cause of the increase in the number of red blood cells.
Usually, the treatment aims to decrease the amount of red blood cells, make the blood more fluid and thus relieve symptoms and reduce the risk of complications. In the case of polycythemia vera, for example, it is recommended to perform therapeutic phlebotomy, or bleeding, in which excess red blood cells are removed.
In addition, the doctor may recommend the use of medications, such as aspirin, to make the blood more fluid and reduce the risk of clots, or other medications, such as Hydroxyurea or Interferon alfa, for example, to decrease the amount of red blood cells.
