Oliguria

During the day, an adult normally excretes 1-2 liters of urine, which is 50-80% of the fluid intake. If the amount of urine excreted per day is less than 500 ml (oliguria) or more than 2000 ml (polyuria), the situation is considered pathological. Decreased urine output (oliguria) occurs with inadequate fluid supply to the body, fever, vomiting, diarrhea, toxemias, acute nephritis, and others. The comparative daily urine mass of an adult fluctuates widely (from 1.012 to 1.035). This depends on dietary habits and rhythm, environmental conditions, work rhythm, etc. (sweating, etc.). During oliguria (e.g., in acute nephritis), urine density increases. In cases of severe renal parenchymal damage (acute diffuse nephritis), kidney stones (obstructed ureters), poisoning with lead, mercury, arsenic, or under severe psychological stress, urine excretion may completely cease (anuria). Prolonged anuria leads to uremia. Normally, more urine is excreted during the day than at night (ratio from 4:1 to 3:1). In some pathologies (early stages of heart decompensation, cases of cystitis), more urine is excreted at night than during the day (nocturia).

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė