When asymptomatic hematuria is present, don’t forget the ophthalmologic examination, such as hereditary nephritis (Alport’s syndrome), renal hypertension and other patients with changes in the fundus. Classification of the etiology of asymptomatic hematuria: 1. glomerulogenic IgA nephropathy, thin basement membrane nephropathy (benign familial hematuria), hereditary nephritis (Alport’s syndrome), focal glomerulonephritis due to other causes. 2. Non-glomerular origin Upper urinary tract: stones, pyelonephritis, polycystic kidney, medullary spongy kidney, hypercalciuria and/or hyperuricuria (without stones), kidney injury, papillary necrosis, ureteral stenosis and hydronephrosis, renal infarction or arteriovenous malformation, left renal vein compression (nutcracker phenomenon), renal tuberculosis, renal cell carcinoma, renal pelvis/ureteral migratory cell carcinoma. Lower urinary tract: cystitis, prostatitis or urethritis, benign bladder/ureteral polyps or tumors, bladder cancer, prostate cancer, urethral stricture. 3. Uncertain etiology Sports hematuria, benign hematuria (as yet unexplained microscopic hematuria), pseudohematuria (usually accompanied by meatus hematuria), excessive anticoagulation (warfarin, etc.) Strenuous exercise, menstrual contamination, mild trauma to the urinary tract and after sexual intercourse can cause transient hematuria, so when asymptomatic microscopic hematuria is diagnosed, urine routine needs to be rechecked after 48 hours to exclude pseudoscopic hematuria.