Erythrocytes
Erythrocytes are red blood cells that are normally absent or present in minimal amounts in urine (0–1 per high power field in men and 0–3 in women under the microscope).
The presence of erythrocytes in urine (hematuria) may indicate damage to the kidneys or urinary tract, inflammatory processes, trauma, infections, urolithiasis, tumors, and other pathologies.
There are two types of erythrocytes in urine:
- Unaltered (contain hemoglobin): bright red, found in diseases of the urinary tract and kidneys such as pyelonephritis, tuberculosis, and urolithiasis.
- Altered (lysed): colorless, without hemoglobin, appear after prolonged contact with acidic urine, characteristic of glomerulonephritis and circulatory disorders in the kidneys.
Hematuria can be microscopic (microhematuria) — without visible change in urine color, and macroscopic (macrohematuria) — with visible discoloration.
To clarify the causes of hematuria, additional tests are performed: 24-hour urine analysis, Thompson test, blood laboratory tests, and instrumental examinations.
Proper urine collection and preparation for analysis are important for obtaining reliable results.
The detection of erythrocytes in urine requires consultation with a physician for timely diagnosis and treatment of possible diseases.