What disease does occult blood in urine indicate?

Occult blood in urine refers to the presence of red blood cells in the urine, which is an abnormal indicator in routine urinalysis. This condition is usually not visible to the naked eye and is also known as microscopic hematuria. The main causes of occult blood in urine include:

1. Glomerulonephritis: Kidney inflammation may cause red blood cells to leak into the urine.

2. Kidney stones: Stones passing through the urinary tract may damage the urinary tract, leading to bleeding.

3. Urinary tract infections: Inflammatory urinary tract diseases such as cystitis and urethritis may also cause occult blood in urine. Inflammation caused by infection may irritate the urinary mucosa, making it fragile, and the passage of urine may cause tiny blood vessels to rupture.

4. Tumors: Tumors in any part of the urinary system, such as the kidneys, bladder, or ureters, can cause occult blood in urine.

5. Vascular abnormalities: Conditions such as glomerular disease can affect the kidney's filtration function, allowing red blood cells to enter the urine.

6. Medication factors: Anticoagulant drugs, chemotherapy drugs, and others may also cause occult blood in urine.

7. Exercise-induced hematuria: Some individuals may experience transient occult blood in urine after intense physical activity; this is usually harmless and resolves on its own.