Polycythaemia Classification Quiz

Study Notes

Pseudopolycythaemia and Clinical Symptoms

Main reason for clinical symptoms in pseudopolycythaemia is increased plasma volume, not red blood cell (RBC) mass.
Symptoms include headache and dizziness due to relative changes in blood chemistry and volume dynamics.

Elevated Hematocrit in Polycythaemia

Symptom resulting from elevated hematocrit is increased blood viscosity, which can lead to complications such as headaches and hypertension.

Visual Problems in Polycythaemia

Individuals with polycythaemia experience visual problems due to reduced blood flow to the retina caused by elevated blood viscosity affecting microcirculation.

Effects of Increased Blood Viscosity

Increased blood viscosity in polycythaemia leads to sluggish circulation, raising the risk of thrombosis and organ ischemia, increasing workload on the heart.

Thrombotic Episodes in Polycythaemia

Elevated red blood cell mass and blood viscosity predispose individuals to thrombotic episodes, significantly increasing the risk of stroke and heart attacks.

Defining Feature of Polycythaemia

Defining feature of polycythaemia is an elevated RBC count, typically greater than 6 million/mm³, indicating abnormal erythrocyte production.

Mutation in Polycythaemia Vera

Polycythaemia Vera is primarily caused by a mutation in the JAK2 gene, leading to uncontrolled RBC production.

RBC Count in Polycythaemia

In secondary polycythaemia, RBC count typically rises to 6 to 7 million/mm³ as a response to underlying conditions like chronic hypoxia.

Main Cause of Secondary Polycythaemia

Main cause of secondary polycythaemia is hypoxia, often resulting from chronic lung disease or living at high altitudes, prompting an increase in erythropoietin production.

Physiological Polycythaemia and Altitude

Natives living at altitudes above 2,500 meters (approximately 8,200 feet) often experience physiological polycythaemia due to lower atmospheric oxygen levels.

Primary vs. Secondary Polycythaemia

Primary polycythaemia, such as Polycythaemia Vera, results from intrinsic factors such as genetic mutations; secondary polycythaemia is triggered by external factors like hypoxia and increased erythropoietin levels.

Description

Test your knowledge on the classification of polycythaemia based on pathophysiology, including absolute and relative/pseudopolycythaemia. Learn about primary polycythaemia (polycythaemia vera) and its characteristics such as high RBC count and hematocrit levels.