Difference between urine occult blood and urine red blood cells

Urine occult blood and urine red blood cells are the two most common concepts when people do urine tests. Urine occult blood refers to the presence of blood in the urine, while urine erythrocytes refer to the presence of red blood cells in a urine test. Therefore, the two are actually the same. In clinical examinations, urine occult blood is the standard. There are many reasons for the appearance of occult blood in urine, such as inflammation, infection, tumor, kidney disease or stones.

1. What is occult blood in urine?

Occult blood refers to the presence of an increase in red blood cells during a routine urine test. In a few cases, it can be called urine occult blood, which is indicated by "+" or "-" in the urine red blood cell (RBC) item in the urine routine examination form. Generally, when the red blood cells are normal, the urine red blood cell column will be negative, indicated by a - sign; when the number of red blood cells increases, that is, urine occult blood appears, it is urine occult blood positive, indicated by a +. If urine occult blood is positive, it indicates that the examiner may have urinary tract tumors, nephritis infection and other diseases.

Urine occult blood alone cannot be used as a basis for diagnosing a disease, because normal people may also have urine occult blood under normal circumstances, but normal urine occult blood is negative. Normal urine contains very few red blood cells, so urine occult blood is negative. When the red blood cells in the urine reach a certain number, the results of routine urine examination will be positive.

2. What does occult blood + mean

If there are more than 2 red blood cells per high-power field of view in the urine after centrifugation under a microscope, it is called hematuria. Under a high-power microscope, 10 red blood cells are counted as "+, 1+ or +1", 20 are counted as "++, 2+ or +2", 30 are counted as "+++, 3+ or +3", and 40 are counted as "++++, 4+ or +4". In other words, the more plus signs there are, the more severe the damage to the kidney's intrinsic cells.

The appearance of “+” indicates that the intrinsic cells of the kidney have begun to be damaged, and the filtration function of the kidney has begun to be impaired by the immune mediator complex. If it is not effectively treated, the number of damaged and proliferating glomeruli will increase, and the degree of kidney damage will gradually increase.

3. Causes of positive urine occult blood

First, kidney diseases, glomerulonephritis, nephrotic syndrome, systemic lupus erythematosus nephritis, etc. can cause occult blood in the urine.

Second, inflammation. Whether it is glomerulonephritis, pyelonephritis or cystitis, there may be potential bleeding in the urine

Third, stones. Stones in the kidneys, ureters, bladder, etc. may cause occult blood in the urine.

Fourth, tumors. Malignant or benign tumors of the kidneys, bladder, or ureters may cause occult blood in the urine.

Fifth, the main clinical manifestation of hereditary nephritis (Alport syndrome) is occult blood in the urine.