A patient has a urine output of less than 100 mL in 24 hours. This condition is called:

Appeared in: NORCET 9 Mains - 2025

Explanation

Anuria is the correct medical term for a urine output of less than 100 mL over a 24-hour period.
This specific volume threshold distinguishes it from oliguria, which is a less severe reduction in urine output.
The condition indicates a critical failure of the kidneys to produce urine, which can be caused by severe kidney damage, end-stage renal disease, or a complete obstruction of the urinary tract.

Option A: Nocturia refers to the act of waking up during the night to urinate. It is a symptom related to the frequency and timing of urination, not the total 24-hour volume.
Option C: Polyuria is the opposite of the condition described. It signifies an excessive or abnormally large production of urine, typically defined as more than 2.5 or 3 liters per day.
Option D: Oliguria refers to a low urine output, but the clinical definition is a volume of less than 400 mL per day. The value in the question (less than 100 mL) is more severe and falls into the specific category of anuria.

Visual 1: Chart: A visual chart comparing the definitions and 24-hour volume thresholds for Anuria, Oliguria, Polyuria, and Normal urine output. This helps in quick recall of the specific numerical values.

Clinical Relevance

Nursing practice connection: Use the key finding related to Terminology of Urinary Output Volumes to guide bedside assessment, documentation, and the next nursing action.
Monitoring urine output is a fundamental nursing assessment. It provides a rapid, non-invasive indication of a patient's fluid status and renal function.
A sudden drop in urine output to oliguric or anuric levels is a critical finding that must be reported to the physician immediately, as it can signal acute kidney injury (AKI), severe dehydration, or shock.
What if? If the patient's output was 350 mL in 24 hours, the condition would be classified as Oliguria, not Anuria. While still a serious concern indicating renal distress, it is a less severe state than anuria and might be managed with fluid resuscitation or addressing the underlying cause before it progresses.

How to Approach the Question

First, identify the key information in the question stem: 'urine output of less than 100 mL in 24 hours'.
Recognize that this is a factual recall question asking for a specific medical definition.
Focus on the numerical value (100 mL) as the primary clue.
Evaluate each option against this specific value. Recall or look up the definitions for each term.
Anuria is defined as <100 mL/day.
Oliguria is defined as <400 mL/day.

Concept Tested & Keywords

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