What does hematuria indicate?

Hematuria specifically refers to the presence of blood in the urine, which can be an indicator of various underlying medical conditions. The identification of blood in urine can arise from numerous sources, including but not limited to urinary tract infections, kidney stones, trauma, tumors, or systemic diseases affecting the kidneys. Therefore, finding blood in the urine necessitates further investigation to determine the exact cause and guide appropriate treatment.

The other choices do not accurately define hematuria. The presence of bacteria in urine pertains to a urinary tract infection, and high protein levels in urine would suggest proteinuria, unrelated to hematuria. Low urine output, or oliguria, refers to the volume of urine produced and does not directly indicate blood presence. Thus, the correct answer effectively encapsulates the clinical significance and the potential implications of hematuria in a patient's health assessment.