What is the significance of RBC presence in urine?

The presence of red blood cells (RBCs) in urine, known as hematuria, is significant primarily because it can indicate conditions such as renal stones or bleeding within the urinary tract. When there are stones present in the kidneys or urinary pathways, they can cause trauma or irritation to the lining of these structures, leading to bleeding. This bleeding results in the leakage of RBCs into the urine. Similarly, hematuria can also arise from other sources of bleeding, such as damage or inflammation in the kidneys, ureters, bladder, or urethra. Identifying RBCs in a urinalysis necessitates further investigation to determine the underlying cause, which may involve imaging studies or additional laboratory tests.

While RBCs can occasionally be found in other conditions, such as infections (often accompanied by other indicators like white blood cells or bacteria), dehydration, or high protein levels, these scenarios do not primarily connect to the presence of RBCs in urine in the same direct and significant way as the presence of renal stones or bleeding does.