High Quality Content by WIKIPEDIA articles! In medicine, hemoglobinuria or haemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is often associated with hemolytic anemia, in which red blood cells (RBCs) are destroyed, thereby increasing levels of free plasma hemoglobin. The excess hemoglobin is filtered by the kidneys, which release it into the urine, giving urine a red color.