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Urine Lysine-to-Creatinine Ratio

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

A urine test that measures lysine relative to creatinine, helping evaluate how much lysine the body is excreting.

Quick summary

["This test can help identify excessive urinary lysine excretion, which may occur with inherited disorders of lysine metabolism."]

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

Key facts at a glance

LOINC
22679-5
Short code
Lysine/Creat Ur-sRto
Synonyms
Lysine/Creat Ur-sRto
Category
kidney
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 amount of lysine in urine compared with the amount of creatinine. Creatinine is used as a reference to account for differences in urine concentration.

Why might I need this test?

It may be used when evaluating suspected inherited disorders of amino acid metabolism, particularly if an infant or child has developmental concerns, seizures, unusual symptoms, or an abnormal newborn screening result.

How is the test performed?

A urine sample is tested to determine the relative amounts of lysine and creatinine. The result is reported as a ratio rather than as a urine concentration alone.

How do I prepare for the test?

Follow your healthcare professional's collection instructions. Depending on the test, a first-morning urine sample may be requested, and changes in diet or lysine supplements should be reported to the laboratory.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine lysine/creatinine ratio

Frequently asked questions

Does this test diagnose a specific condition?
No. An abnormal result may suggest a problem with lysine metabolism but generally must be interpreted alongside symptoms, medical history, diet, and additional laboratory tests.
Why is creatinine included in the result?
Creatinine provides a reference for urine concentration. Including it helps compare lysine excretion between samples without relying on urine volume alone.
Can diet or supplements affect the result?
Yes. Recent lysine intake, protein-rich meals, and lysine supplements may affect urinary lysine levels, so the testing provider should be told about them.
  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