The term hematuria is used to describe the presence of intact red blood cells in the urine. The urine may be cloudy/red or pink in color and red blood cells (RBCs) are visible upon microscopic examination.
If RBCs have been destroyed, hemoglobin will be present in the urine. The term, hemoglobinuria, is used to describe this condition. The color of the urine will be pink or red but clear rather than cloudy.
The presence of only five RBCs per microliter of urine is considered to be clinically significant. For this reason, a chemical test is needed to detect quantities of blood too small to change the color of the urine. Microscopic examination is used to differentiate between hematuria and hemoglobinuria, if the chemical reagent strip is positive for blood.