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The Hematocrit Test – How and Why It Is Performed

Introduction to the Hematocrit Test:

The hematocrit test determines the percentage of whole blood that is made up of red blood cells (RBCs). A normal hematocrit test result for males is about 45% (38-50%) of blood volume. For females, it is about 40% (35-44%) of blood volume.

An image showing the graph used in the hematocrit test.
The hematocrit test.
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The test results are affected by RBC number, RBC size, and plasma volume. A low test result can be produced by a low number of RBCs, microcytosis (small RBCs), or an increased plasma volume. A high test result can be produced by a high number of RBCs (polycythemia), macrocytosis (enlarged RBCs), or a low plasma volume.

Test Procedures:

  1. First, a finger is image descriptionlanced and a small drop of blood is allowed to accumulate.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Animation of the index finger being lanced and the blood accumulating.
Finger is lanced and blood accumulates.
  1. Blood is image descriptiondrawn up into a heparinized (anticoagulant) glass tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Animation of the blood being drawn into a heparinized tube.
Blood being drawn up into a heparinized tube.
  1. One end of the blood-filled tube is image descriptionsealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Animation showing a blood filled tube being sealed with clay.
Blood-filled tube being sealed with clay.
  1. The blood-filled tubes are placed in a centrifuge and image descriptionspun until the plasma and formed elements separate.
Blood-filled tubes being spun in a centrifuge.
  1. The glass tube is image descriptionmoved across a reader board until the bottom of the RBC column is at 0% and the top of the plasma column is at 100%
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
Animation showing the blood filled tube being moved across the test.
The glass tube being moved across the reader board.
  1. The percentage of RBCs in the blood is determined by image descriptiontracing the grid lines near the top of the red column to the % scale.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Animation showing how the red blood cell percentage is determined by tracing along the grid lines.
Determining the percentage of RBCs in the blood.

Test yourself:

Hematocrit Test Quiz