Polycythaemia Vera
Polycythaemia vera (PV) is a rare, slow-growing blood cancer in which the bone marrow produces far too many red blood cells. The resulting thickening of the blood raises the risk of blood clots, stroke, and heart attack. Most cases are driven by a mutation in the JAK2 gene and are diagnosed incidentally on a routine blood count.
Key points
- A mutation in the JAK2 gene drives most cases, prompting the bone marrow to churn out excess red blood cells.
- Itchy skin that flares after a hot bath or shower, along with headaches and an enlarged spleen, are among the recognised symptoms.
- Regularly drawing off a unit of blood is typically tried first, with hydroxycarbamide added if that fails to control counts.
Recognising the signs
Symptoms arise from sluggish, thickened blood and elevated blood pressure within the vessels. Common complaints include persistent headaches, dizziness, blurred vision, and a flushed, itchy skin, particularly after a hot bath or shower (aquagenic pruritus). Some people notice fullness or discomfort on the left side of the abdomen caused by an enlarged spleen.
Seek urgent medical attention if you experience sudden weakness on one side of the body, slurred speech, chest pain, or severe shortness of breath, these may signal a clot or stroke requiring emergency care.
How polycythaemia vera is managed
Treatment focuses on reducing blood viscosity and cutting clot risk. Regular venesection (removing a unit of blood) is the first step for many patients. When venesection alone is insufficient, cytoreductive therapy is added; hydroxycarbamide is the most widely used agent and sits within oncology support care. Low-dose aspirin is typically given alongside to thin the blood further.
PV requires lifelong monitoring by a haematologist, as a small proportion of cases can transform over time into myelofibrosis or acute leukaemia.