What is the disease of occult blood in women's urine

If female friends experience some uncomfortable symptoms, they should go to the hospital for a comprehensive gynecological examination, and a urine test is indispensable in the examination. This test can most intuitively detect whether there are any abnormal changes in your urine, especially the occult blood test. If there are abnormalities, it may be due to muscle damage or other ischemic diseases. Regardless of the reason, a more detailed examination is needed next time.

Occult blood

If the urine occult blood test using the test strip is positive, you should highly suspect: ① hematuria. It is common in some diseases of the kidney and urinary system (such as glomerulonephritis, pyelonephritis, renal cysts, urinary system stones and tumors, etc.), extra-renal diseases, trauma, strenuous exercise and some drugs (such as cyclophosphamide). ②Hemoglobinuria. It is common in intravascular hemolysis (such as transfusion reactions and hemolytic anemia), severe burns, strenuous exercise (march hemoglobinuria) and some infections. In addition, hemoglobin can also be released in the urine after the destruction of red blood cells. ③Myoglobinuria.

It is common in muscle injuries (such as severe crush injuries, surgery, ischemia), muscle wasting diseases, dermatomyositis, excessive exercise, etc. If the urine occult blood test is positive, further microscopic examination should be performed to confirm the presence of red blood cells. When the urine contains heat-labile enzymes or bacteriuria, the test result will be a false positive; when there is a large amount of vitamin C in the urine, the test result will also be a false negative.

[Normal reference value] Negative.

Bilirubin

If the blood bilirubin level is elevated, the urine test strip method can detect positive bilirubin. Certain liver diseases, such as viral hepatitis, can cause elevated urine bilirubin. If blood bilirubin is clearly elevated but urine bilirubin is negative or suspected to be positive, specific laboratory verification is recommended. Positive urine bilirubin may also be caused by obstruction of the intrahepatic bile duct, which is common in common bile duct stones, pancreatic head cancer, and intrahepatic inflammation, where increased pressure in the duct causes bile reflux.

The metabolites of some drugs (such as pyrimidine) in urine are colored at low pH, which is close to the color of the reaction of the test substance itself, and a false positive may occur; bilirubin is easily decomposed by light, and if the urine is not fresh or has been exposed to light for too long, a false negative may occur in the test result; a large amount of vitamin C or nitrite in the urine will reduce the sensitivity of the test strip method.

[Normal reference value] Negative.

Urobilinogen

After direct bilirubin is secreted into the small intestinal cavity, it undergoes a series of reactions to generate a series of products, with urobilinogen as one of the main products. About 20% of urobilinogen is reabsorbed and enters the enterohepatic circulation, of which a small amount (2% to 5%) enters the bloodstream and is filtered from the glomerulus. The test results combined with the urine bilirubin results analysis can help in the differential diagnosis of jaundice. Some drug metabolites in urine can react with reagents in the test strip, resulting in false positives; porphyrinogen, indole compounds and melanogen in urine also often lead to false positives; if formaldehyde is used as a preservative or the specimen is improperly stored, urobilinogen will be oxidized into urobilin, and the test result may be a false negative.