PCV or HCT  is the volume of packed red cells obtained after centrifugation of a sample of anticoagulated venous or capillary blood. It is expressed either as a percentage of volume of whole blood or as a decimal fraction.

 Factors that can affect the Haematocrit:

• Living at a high altitude
• Pregnancy
• Significant recent hemorrhage
• Recent blood transfusion
• Severe dehydration

 Causes associated with high haematocrit:

• Dehydration
• Polycythemia Vera (a myeloproliferative disorder associated with the production of excessive numbers of red cells)
• Lung or heart disease
• Administering of Testosterone supplement therapy
• Dengue fever (high haematocrit is a danger sign of an increased risk of dengue shock syndrome)
• Chronic obstructive pulmonary disease (COPD)
• Other pulmonary conditions associated with hypoxia
• Doping or erythropoietin (EPO)
• Use of Anabolic androgenic steroid (AAS)
• Capillary leak syndrome

 Causes associated with low haematocrit:

• Associated with long-term illness, infection or a white blood cell disorder such as leukemia or lymphoma
• Vitamin or mineral deficiencies
• Lung or heart disease Recent or long-term hemorrhage.

Erhabor O, et al. Interpretation of Full Blood Count Parameters in Health and Disease. Haematol Int

J 2021, 5(1): 00180.