Hematuria is one of the most common symptoms of kidney disease. Hematuria can be divided into two categories according to clinical manifestations: symptomatic and asymptomatic. Symptomatic hematuria means that the affected person has some other urinary symptoms besides hematuria, such as edema, proteinuria, hypertension, renal insufficiency, urinary frequency, urinary urgency, urinary pain, back or abdominal pain, etc. Asymptomatic hematuria refers to patients with no other symptoms except hematuria. It is more difficult to diagnose because it lacks other symptoms that can be used as reference for diagnosis. Asymptomatic hematuria is divided into glomerular and non-glomerular according to the source of urinary red blood cells by Peng Guijun, Department of Nephrology, The First Affiliated Hospital of Henan College of Traditional Chinese Medicine. Asymptomatic glomerular hematuria should firstly exclude the small amount of residual hematuria during the recovery period of acute nephritis and purpura nephritis. In addition, hereditary nephritis and benign familial hematuria should be considered. Asymptomatic glomerular hematuria after excluding the above diseases can be further clarified by renal puncture biopsy. Common pathological types of asymptomatic glomerular hematuria in patients include IgA nephropathy, thylakoid proliferative nephritis, mild lesions, focal segmental glomerulosclerosis, and thin basement membrane disease. Common causes of asymptomatic non-glomerular hematuria include urologic malformations, renal calculi, idiopathic hypercalciuria, left renal vein compression syndrome, pharmacologic hematuria, and exercise hematuria. Renal puncture biopsy is the gold standard for the diagnosis of kidney injury, and can be considered if the following conditions are met: 1. Those with urine sediment microscopic examination of red blood cells meeting the diagnostic criteria of glomerular hematuria. 2. Asymptomatic hematuria persisting or appearing intermittently for more than 6 months. 3. Family history. 4. Urine protein quantification >1.0g/24H, qualitative (+). Ultrasound examination is necessary to detect abnormalities, stones, tumors, blood clots and surrounding tissues of the urinary system. Repeated multiple urine tests are helpful in detecting asymptomatic microhematuria, and are usually repeated 2-3 times in 2-3 weeks. It is necessary to do urine sedimentation red blood cell morphology and mean volume measurement test for judgment.