What does oliguria mean?
Oliguria is the medical term for producing less urine than normal. It is used when the kidneys output an unusually small volume of urine, a finding that may accompany dehydration, reduced blood flow to the kidneys, or kidney injury and therefore often requires clinical evaluation. The word is especially common in hospital medicine, nephrology, and intensive care, where urine output is regularly monitored. Although “low urine output” and “reduced urine output” are plain-language explanations, the technical term is useful in medical documentation and discussion. Oliguria should be distinguished from anuria, which means that urine production has stopped altogether. It is also different from merely infrequent urination: a person may urinate rarely while producing a normal total volume. The related adjective is “oliguric,” as in “oliguric kidney injury.”
nounOliguria is the production of less urine than is considered normal, often indicating impaired kidney function or inadequate blood flow to the kidneys. It is a clinical sign rather than a disease in itself.
- The medical condition of producing an abnormally small amount of urine.
"The patient developed oliguria after surgery and was closely monitored for signs of kidney injury."
"Severe oliguria was noted on the second day of hospitalization."
"The physician explained that oliguria can be a warning sign of dehydration or kidney dysfunction."
Usually used in the singular in clinical writing; the plural is uncommon.
"The report documented oligurias in several patients receiving intensive care."
Oliguria comes from Greek roots meaning “little urine” — a compact clinical name for the kidneys producing too little.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does oliguria come from?
Oliguria was formed in the early 19th century from the Greek adjective oligos, meaning “few” or “little,” and ouron, meaning “urine.” The combination literally expresses the production of “little urine.” The prefix olig- also appears in related English words such as oligarchy, oligotrophic, and oligocene, although these have developed independently or through different combinations of Greek elements.
Related word forms
How oliguria is actually used
This is a formal medical term used in clinical reports, research, and healthcare. It is not a general synonym for simply urinating infrequently, since reduced urine volume can reflect changes in fluid intake, kidney function, blood pressure, or other physiological factors.
Easily confused with oliguria
Oliguria means that some urine is still being produced, whereas anuria means the complete absence of urine production.