What does the presence of microscopic hematuria typically indicate?

The presence of microscopic hematuria, which is defined as the presence of red blood cells in urine that can only be detected under a microscope, often indicates various underlying conditions. Among these, the presence of renal calculi, or kidney stones, is a common cause. When kidney stones move within the urinary tract, they can irritate the lining of the urinary system, leading to bleeding, which manifests as hematuria. This bleeding is typically microscopic at initial stages or depending on the size and movement of the stones.

While other conditions such as urinary tract infections or renal failure can also lead to hematuria, they often present with additional symptoms or signs, making renal calculi a significant consideration when addressing isolated cases of microscopic hematuria. Each potential condition can produce hematuria, but the association of stones and resultant urinary irritation is particularly noted in clinical practice.