What should I do if the urine occult blood has a "plus sign"? It depends on whether the blood in the urine comes from inside or outside the kidney.

A friend left a message saying that during the routine urine test, there was a "+" in the urine occult blood item. He asked Huazi if this meant hematuria, indicating that there was something wrong with his kidneys? Huazi replied that if there was only one positive urine occult blood in the routine urine test and no other abnormalities, it did not indicate a problem and there was no need to worry too much. He should rest more, drink more water, and go for another urine test after a while, and then look at the results.

1. Urine occult blood test is prone to false positives. Urine occult blood test in routine urine test uses urine to react with reagent (test paper). If there is hemoglobin in urine, the color of the reagent (test paper) will change. The depth of the color change reflects the amount of hemoglobin in urine.

However, urine occult blood tests are prone to false positives, which does not necessarily mean that hematuria has occurred. If there are bacteria in the urine, or if there is mild muscle damage due to exercise, or if there is hemolysis in the blood vessels, urine occult blood will have a positive reaction, but this is not hematuria.

Hematuria refers to the presence of red blood cells in the urine. Generally, a urine sediment examination is required, and red blood cells can only be seen under a microscope to be defined as hematuria.

2. Will urine turn red after hematuria? Many people think that urine will turn red if hematuria occurs. However, if it is mild hematuria, it cannot be seen with the naked eye, and the body will not feel uncomfortable. It can only be seen through a microscope. This situation is also called microscopic hematuria.

Only when severe hematuria occurs will the urine change color significantly, appearing like meat washing water, sauce wine color, bright red, or even blood clots. This condition is called gross hematuria.

However, there are other situations that can cause urine to turn red. For example, if you eat foods such as beets and red dragon fruit, or take drugs such as rifampicin and metronidazole, your urine may also turn red.

3. Check whether the hematuria comes from inside or outside the kidney. If red blood cells are found under a microscope, it is necessary to determine whether the hematuria comes from inside or outside the kidney to roughly estimate the severity of the disease. If the hematuria comes from inside the kidney, the red blood cells will be squeezed by the glomerular filtration membrane and deformed. If most of the red blood cells are deformed under a microscope, the hematuria is likely to come from inside the kidney. It is common in various kidney diseases such as glomerulonephritis, hypertensive nephropathy, and diabetic nephropathy.

If most of the red blood cells are normal in shape, the hematuria is likely to come from extrarenal sites such as the renal pelvis, ureter, and bladder. It is often caused by inflammation, stones, tumors, trauma, and other diseases in the above-mentioned sites.

Fourth, it is important to see whether there is proteinuria. Relatively speaking, hematuria from outside the kidney is easy to treat, as long as the primary disease is treated. Most of the diseases that cause renal hematuria are chronic diseases, which are relatively difficult to treat. If renal hematuria occurs, pay attention to whether there is protein in the urine. Proteinuria is more significant than hematuria in determining kidney damage.

If proteinuria occurs, it means that kidney damage is serious. It is necessary to find the cause and actively treat it. For example, anti-inflammatory treatment, strict control of blood pressure and blood sugar, and reduction of proteinuria are needed.

If there is no proteinuria, but only simple renal hematuria, it may be latent glomerulonephritis or hereditary thin basement membrane nephropathy. Generally speaking, the harm is minor and no treatment is required.

To summarize, in a routine urine test, if "+" appears in the urine for occult blood, it does not mean that hematuria has occurred. Many people only have a transient positive reaction or a false positive reaction, and a urine sediment test is required to confirm whether there is hematuria. If it is hematuria, it is also necessary to determine whether it comes from inside or outside the kidney, and whether there is proteinuria in order to carry out targeted treatment. I am pharmacist Huazi, welcome to follow me and share more health knowledge.