Hemoglobinuria is the presence of hemoglobin in the urine, typically resulting from the breakdown of red blood cells (hemolysis). This condition can occur due to various causes, including hemolytic anemia, infections, or physical trauma. The presence of hemoglobin in urine can lead to a dark or reddish color and may indicate underlying health issues that require medical evaluation. Diagnosis often involves urine tests and further investigation to determine the cause of the hemolysis.