Hemoglobinuria

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Why is the Test Performed?

This test may be used to help diagnose:

• hemolytic anemia
• infections
• the breakdown of red blood cells from a transfusion reaction or other process

Hemoglobin is composed of a molecule called heme, and a protein globin. Together, they form a molecule called hemoglobin, which is within red blood cells. The purpose of hemoglobin is to transfer oxygen and carbon dioxide.

In the lungs, the hemoglobin picks up molecules of oxygen. Then, the hemoglobin and oxygen are carried within red blood cells to tissues that need oxygen. The hemoglobin gives up the oxygen and picks up carbon dioxide from the tissue -- which is then carried back to the lungs again in a continuous cycle.

Red blood cells have an average life span of 120 days. After this time, they are broken down into their components for reassembly into a new red blood cell. This typically takes place in the spleen, bone marrow, and liver. If the red blood cells are hemolyzed (broken down) in the blood vessels, the components are free in the blood stream. Free hemoglobin is typically reprocessed. If the level of hemoglobin in the blood rises too high, then hemoglobin begins to appear in the urine.