Reduced urine output is normal or abnormal kidney function should be judged according to the cause of reduced urine output, if it is renal oliguria caused by renal causes, kidney function is usually abnormal. If it is caused by physiological factors or urinary stones, renal function may be normal. It is recommended to consult a doctor in time to identify the cause of the disease and treat the symptoms. 1. Renal oliguria: acute nephritis, interstitial nephritis and other renal diseases will lead to destruction of renal function, decreased filtration capacity of the kidneys, reduced filtration, and decreased urine output. 2. Physiological factors: when drinking too little water or sweating more, the urine volume will be reduced at this time, not oliguria caused by renal insufficiency. If you drink more water, the urine output will return to normal. 3. Urinary stones: patients with urinary stones generally have normal kidney function, stones lead to urethral blockage, urine retention in the kidneys, ureters and bladder, unable to pass through the urethra out of the body. Release the obstruction, the urine volume can usually return to normal. Patients with reduced urine output are advised to consult regular hospitals for standardized treatment under the guidance of physicians.