What is Polycythaemia?
Polycythaemia is a condition characterized by an abnormal increase in red blood cells. There are two main types:
Secondary Polycythaemia:
- Increase in red blood cell (RBC) count up to 6-7 million/mm3.
- Caused by tissue hypoxia (lack of oxygen) due to:
- High altitudes
- Respiratory problems
- Lung or cardiovascular diseases
- Hypoxia leads to increased production of erythropoietin, a hormone that stimulates RBC production.
Polycythaemia Vera (Primary Polycythaemia; Erythraemia):
- A pathological condition affecting erythropoiesis (RBC production).
- Caused by a genetic aberration in the haemocytoblastic cells responsible for RBC production.
- RBC count can reach 7-8 million/mm3.
- Haematocrit (the volume percentage of RBCs in blood) may be 60-70%.
Symptoms of Polycythaemia:
Both types of polycythaemia can lead to:
- Increased blood volume
- Increased blood viscosity (thickness) – up to 10 times that of water (normal is 3 times)
- Hypertension
- Flushed skin
- Headaches
- Blurred vision
- Dizziness
- Night sweats
- Widespread itching
- Enlarged spleen
Potential Complications:
Polycythaemia can increase the risk of:
- Increased bleeding
- Blood clots (thrombi and emboli) which can lead to:
- Myocardial infarction (heart attack)
- Stroke
- Myelofibrosis (bone marrow scarring)
- Acute leukaemia
Diagnosis and Treatment:
Diagnosis of polycythaemia typically involves:
- Physical examination
- Blood tests
- Ruling out other possible causes
Treatment aims to reduce blood thickness and prevent complications. Options include:
- Venesection: Regularly removing blood from the body.
- Medications:
- Aspirin (to reduce blood clotting)
- Anti-cancer drugs
- Radioactive phosphorus
- Interferon
With proper treatment, most patients with polycythaemia can live for 10-15 years.
