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24-Hour Urinary Volume (Kidney Function)

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of urine produced in a 24-hour period, helping assess how well your kidneys are filtering waste and fluid from your blood.

Quick summary

["Understanding your kidney function through urine volume helps identify fluid balance and kidney efficiency."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
15305-6
Short code
Volume Kidney-R from HWL
Synonyms
Volume Kidney-R from HWL
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-derived-hwl
CPT
86430
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why It’s Done

Your doctor may order this test if they suspect conditions like kidney disease, dehydration, or overhydration. It can also help diagnose issues like kidney failure, urinary tract blockages, or improper hormone regulation that affects fluid balance.

How It Works

You’ll collect all urine for a full 24 hours, typically starting after a morning void. The urine is stored in a container, and the total volume is measured at the end of the period. This provides a clear picture of your daily fluid output.

Sample Collection

You’ll need to empty your bladder at the start of the 24-hour period (often after waking up) and discard that urine. Then, collect every drop of urine for the next 24 hours, including overnight. Label the container with your name and the start/end times.

What to Expect

The process is straightforward but requires consistency. You’ll need to keep a log of all urine output, including any accidents. Drink fluids as usual unless instructed otherwise, but avoid diuretics or medications that affect urine production.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low urine volume may indicate dehydration, kidney problems, or conditions like heart failure or liver disease. High urine volume could signal diabetes insipidus, kidney disease, or excessive fluid intake. Abnormal results often prompt further evaluation for underlying health concerns.

Short name

24-Hour Urine Volume

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–2 weeks after the test is completed, depending on lab processing times.
What does a low urine volume mean?
A low urine volume could suggest dehydration, kidney dysfunction, or conditions that restrict fluid reabsorption in your kidneys. Your doctor may recommend additional tests to determine the cause.
Can I drink fluids normally while collecting urine?
Yes, you can drink fluids as usual unless your doctor specifies otherwise. However, avoid excessive diuretics or medications that may alter urine output during the collection period.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy