Hemoglobin in urine

Up to a million erythrocytes per day are excreted in the urine of completely healthy people. This very small amount cannot be demonstrated by conventional chemical tests. Occurrence of a larger number of erythrocytes ( 'hematuria' , erythrocyturia) or penetration of free hemoglobin, or muscle myoglobin, into definitive urine ( hemoglobinuria  or myoglobinuria) is almost always a pathological finding.  'Macroscopic hematuria'  is observed with the naked eye; the urine is pinkish (comparable to water from washed meat) and hemoglobin can be detected spectroscopically in it. There is at least 1 g of hemoglobin per liter in the urine. In massive hemoglobinuria, the urine may be dark beer (hemoglobin degradation to hematin]).  'Microscopic hematuria'  can only be detected biochemically.