The presence of hemoglobin in the urine, as in blackwater fever.
Abnormal presence of free hemoglobin in the urine.
The presence of hemoglobin in the urine without the simultaneous presence of red blood cells. Under normal circumstances, red blood cells break down after a life span of approximately 120 days. The break-down process occurs largely in the spleen. Breakdown in the blood vessels releases free hemoglobin, which is then bound by another protein for reprocessing into new blood cells. If, however, the breakdown process in the blood vessels occurs faster than the protein binding, free hemoglobin appears in the urine and can be detected with a laboratory test. Hemoglobinuria can signal a variety of diseases, primarily hemolytic anemia, glomerulonephritis, sickle cell anemia, thalassemia, and malaria.
The presence in the urine of free hemoglobin. Hemoglobinuria occurs if hemoglobin, released from disintegrating red blood cells, cannot be taken up rapidly enough by blood proteins. The condition sometimes follows strenuous exercise. It is also associated with certain infectious diseases (such as blackwater fever), ingestion of certain chemicals (such as arsenic), and injury.
The presence in urine of hemoglobin free from red blood cells. This condition occurs when the amount of hemoglobin from disintegrating red blood cells or from rapid hemolysis of red cells exceeds the ability of the blood proteins to combine with the hemoglobin.