Skip to content

24-Hour Urine Amino Acids, Substance Concentration

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

Measures amino acids in a 24-hour urine collection to help evaluate amino acid metabolism and how the kidneys handle these nutrients.

Quick summary

["This test can help identify abnormal amino acid excretion and possible metabolic or kidney-related problems."]

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

Key facts at a glance

LOINC
25846-7
Short code
AAA 24h Ur-sCnc
Synonyms
AAA 24h Ur-sCnc
Category
liver
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures the concentration of amino acids in urine collected over 24 hours. Amino acids are building blocks of proteins, and their amounts in urine can reflect metabolism, nutrition, and kidney function.

Why might I need this test?

A clinician may order this test to investigate suspected inborn errors of amino acid metabolism, unexplained changes in growth or development, or symptoms suggesting a problem with kidney handling of amino acids.

How is the test performed?

You collect all urine produced during a full 24-hour period, following the collection instructions provided by the laboratory. The sample is then analyzed, and the result is adjusted using the collection volume and other collection details when appropriate.

How do I prepare for the test?

Follow the laboratory's 24-hour urine collection instructions carefully, including the start and end times and how the container should be stored. Do not fast or restrict your diet unless your clinician specifically instructs you to do so, because this can affect the results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-hour urine amino acids

Frequently asked questions

Why is a 24-hour urine collection needed?
A 24-hour collection captures all urine produced during a complete day, which provides a more representative measurement than a single urine sample. Missed collections or incorrect timing can make the result unreliable.
Do I need to fast before this test?
Fasting is usually not required unless your clinician tells you to follow special instructions. Eating and drinking normally is important because diet can affect how much of each amino acid is excreted.
What if I miss part of the urine collection?
Tell the laboratory or clinician that the collection was incomplete, because this may affect how the result is calculated. Follow their instructions about repeating the collection if necessary.
  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