Definition of Hematuria, microscopic

Hematuria, microscopic: Blood in the urine that is visible only under a microscope. There is so little blood that it cannot be seen without magnification. Microhematuria is in contrast to gross hematuria, in which the blood is so plentiful that it is visible to the naked eye. Hematuria in any amount is abnormal and should be further investigated. It may or may not be accompanied by pain.