There are many causes of pediatric hematuria, commonly caused by diseases of the urinary tract itself, or the manifestation of kidney damage by drugs, or the manifestation of systemic diseases in the urinary tract, which are briefly described as follows: 1) Diseases of the urinary tract include acute nephritis, pyelonephritis, renal tuberculosis, kidney stones, renal vascular malformation, congenital polycystic kidney, renal embryonal tumor, and renal trauma. 2) Hematuria caused by drug damage to the kidney such as kanamycin, gentamicin, sulfonamides, etc. 3) Systemic diseases such as leukemia, hemophilia, aplastic anemia, neonatal natural bleeding disorder, heart failure, endocarditis, rheumatic nephritis, allergic purpura, and transient hematuria caused by strenuous exercise. From the age of onset, the cause of hematuria can vary depending on the age of the child. For example, neonatal hematuria can be seen in neonates with natural hemorrhage, severe hypoxia and asphyxia. In addition to congenital urinary tract anomalies, polycystic kidney and hydronephrosis, hematuria in infancy is also commonly associated with urinary tract infections. Hematuria in preschool and school age is most commonly associated with acute glomerulonephritis, followed by chronic glomerulonephritis, allergic purpura nephritis, and urinary tract infections. From the characteristics of hematuria: 1. The color of hematuria. Bright red is mostly lower urinary tract bleeding, and dark red is mostly upper urinary tract bleeding. 2. The shape of the blood clot. The presence of blood clots in the urine indicates a more serious degree of hematuria. When fresh blood urine is accompanied by blood clots of different sizes and irregular shapes, it indicates bleeding from the urethra in the bladder or prostate. Kidney or ureteral bleeding is dark red, with clots like streaks or earthworms, and may be accompanied by pain and discomfort in the lower back. From the urination situation, the thin line of urine flow suggests urinary tract obstruction, and urination with symptoms such as frequent, painful and urgent urination suggests urinary tract infection or bladder stone. In addition, we should ask whether there is any food or medicine that can cause hematuria, and whether there is a cold or tonsillitis before hematuria, in order to further clarify the diagnosis.