High quantitative leukocytes in the urine are mostly seen in urinary tract infections, and in some cases, in interstitial nephritis. High quantitative leukocytes in urine, if accompanied by symptoms such as urinary frequency, urinary urgency, painful urination, lumbago, fever, etc., and a urine culture test with bacteria, suggest the presence of a urinary tract infection. The urinary tract infections here are acute pyelonephritis and acute cystitis. After antibiotic anti-infection treatment is given, the white blood cells in the urine can basically disappear, and some patients have symptoms such as back pain and rash in addition to white blood cells in the urine. The patient may take painkillers and certain traditional Chinese medicines such as aristolochic acid for a long time, which can cause interstitial nephritis. Interstitial nephritis includes both acute and chronic, but both can show positive urine leukocytes in the urine routine. The prognosis for acute interstitial nephritis is relatively good and most of them can be cured, but chronic interstitial nephritis develops gradually and cannot be cured once it is diagnosed.