Is 914 mL Urine Output in 9 Hours Normal?
Yes, a urine output of 914 mL over 9 hours (approximately 101 mL/hour) is within normal range for a healthy adult, representing adequate hydration and kidney function.
Normal Urine Output Parameters
Your output translates to approximately 2,437 mL over 24 hours if this rate continues, which falls comfortably within normal physiological ranges:
- Healthy adults typically produce 800-2,000 mL of urine per 24 hours 1
- Research suggests that 24-hour urine volumes ≥850 mL indicate adequate fluid intake, particularly when combined with appropriate urine concentration 2
- Studies examining optimal hydration demonstrate that urine volumes sufficient to maintain osmolality ≤500 mOsm/kg (typically >1,000-1,500 mL/24h) represent adequate daily fluid intake to prevent dehydration and reduce disease risk 3
Hourly Rate Assessment
Your hourly rate of approximately 101 mL/hour is well above concerning thresholds:
- Oliguria (abnormally low output) is defined as <0.5 mL/kg/hour for 6 hours, which for a 70 kg adult would be <35 mL/hour 1, 4
- Critical care guidelines identify urine output <45 mL/hour for 2 hours as a marker of renal dysfunction in acute settings 1
- Your output is nearly 3 times the oliguria threshold, indicating normal kidney perfusion and function 5
Voiding Frequency Context
The number of voids matters alongside total volume:
- Up to 7 voids during waking hours is considered normal, though this varies with fluid intake and individual factors 1
- Research shows that ≤6 voids per 24 hours may indicate suboptimal hydration, while your pattern (if extrapolated) would suggest 8-10 voids daily, which is normal 6
- Nocturia (waking ≥1 time to void) affects interpretation, but daytime frequency of every 1-2 hours with adequate volumes is physiologic 1
Important Caveats
Several factors can influence whether this output is appropriate for you specifically:
- Fluid intake must be considered: If you consumed 3+ liters of fluid in those 9 hours, this output might represent incomplete excretion 1, 2
- Medications affecting urine output (diuretics, ACE inhibitors, certain supplements) would increase expected volumes 1, 7
- Time of day matters: Morning urine is typically more concentrated; evening output may be higher volume with lower concentration 1, 3
- Body weight influences absolute thresholds: The 0.5 mL/kg/hour standard means larger individuals should produce proportionally more urine 1, 4
When to Be Concerned
Your output would only be abnormal if accompanied by:
- Excessive thirst or feeling "a little thirsty" throughout the day despite adequate drinking 6
- Very pale, clear urine consistently (suggesting over-hydration or diabetes insipidus) 3
- Symptoms of urinary frequency/urgency causing bother or sleep disruption 1
- Associated symptoms: fever, flank pain, dysuria, hematuria, or systemic illness 1
In isolation, 914 mL over 9 hours represents normal kidney function and adequate hydration status 1, 2, 3.