Hematuria (haematuria) is the presence of red blood cells in the urine. Hematuria is caused by your kidneys allowing blood cells to leak into the urine. If only a small amount of red blood cells exist in the urine, then the urine color may not change and they may only be visible by using a microscope and this is termed microscopic hematuria. Gross hematuria (macroscopic hematuria) is the opposite term, and it can normally be seen that the urine is a different color maybe pink, red or cola-colored. Urine dipstick testing is highly sensitive for blood but lacks specificity, so to confirm microscopic hematuria or gross hematuria then urine microscopy should be used using a freshly voided midstream urine specimen.