Polycythaemia signifies an excess accumulation of red blood cells, resulting in heightened blood viscosity. This condition predisposes individuals to thromboembolic events, including stroke and myocardial infarction. Venesection—termed therapeutic phlebotomy in the clinical setting—rapidly abates red blood cell mass, thereby diminishing the associated thrombotic risk. Chequers Health offers structured venesection services, delivered to the highest safety and efficiency standards, to patients in the Greater Manchester region.

Polycythaemia is usually divided into two main categories:

Primary Polycythaemia (also called polycythaemia vera):

• Caused by a problem in the bone marrow, where too many red blood cells are made.
• It’s a rare blood disorder.

Secondary Polycythaemia

• Happens because of something else in the body that makes you produce more red blood cells.
• Common causes include long-term low oxygen (for example from smoking, lung disease, or living at high altitude) or certain hormone problems.

By removing approximately 350–500 ml of whole blood in a single sitting, venesection achieves several physiological effects of immediate clinical significance:

• A decrease in blood viscosity, which directly correlates with the ease of flow through the vascular tree;
• A lowering of the haematocrit value, expressed as the percentage of blood volume occupied by erythrocytes;
• A reduction in left ventricular and vascular load, translating into mitigation of cardiac strain and enhancement of peripheral perfusion.

In the context of polycythaemia vera (PV), the procedure typically constitutes one aspect of a broader therapeutic strategy, which may concomitantly employ cytoreductive agents to attenuate erythrocyte progenitor-cell hyperplasia.

Optimal haematocrit thresholds are set at:

• Below 45% for male patients
• Below 42% for female patients.

During the initial therapeutic phase, sessions are frequently scheduled on a weekly basis; the maintenance interval is gradually extended according to haematological stability and clinical judgement.

The haematocrit and haemoglobin concentrations are reassessed through scheduled phlebotomy, with results guiding both the timing and volume of subsequent blood removal.

Long-term research shows that following this regimen significantly decreases the risk of venous and arterial blood clots.

Indications for Venesection: Diagnoses and Clinical Indicators Demystified

A Primer on Venesection Therapy: Mechanisms and Techniques

The Role of Venesection in Moderating Serum Ferritin Levels