Hematuria

Hematuria refers to the presence of red blood cells in the urine. It can be classified into microscopic hematuria and gross hematuria based on its severity. Microscopic hematuria means the urine color is normal, but red blood cells can be seen under a microscope. Gross hematuria means that abnormal urine color can be observed with the naked eye. Gross hematuria can appear as a "meat-wash" color, dark tea color, or red, and may even contain blood clots. However, red urine is not always hematuria, as normal individuals may have red urine after taking certain medications or foods, such as rifampicin, aminopyrine, porphyrin, or red dragon fruit. Most cases of hematuria are caused by lesions in the urinary tract, such as inflammation, stones, or tumors, while a small proportion of hematuria is caused by systemic diseases.