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Lysine/Creatinine Ratio, 24-Hour Urine

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

Measures the amount of lysine relative to creatinine in urine collected for 24 hours, helping assess how effectively the kidneys reabsorb lysine.

Quick summary

["An elevated urine lysine-to-creatinine ratio may indicate reduced kidney reabsorption of lysine."]

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

Key facts at a glance

LOINC
56955-8
Short code
Lysine/Creat 24h Ur-Rto
Synonyms
Lysine/Creat 24h Ur-Rto
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 lysine and creatinine in a 24-hour urine collection. Creatinine is used as an adjustment for urine concentration, allowing the amount of excreted lysine to be interpreted more reliably.

Why might I need this test?

It may be used to investigate excessive lysine loss in the urine, especially when kidney disease or an inherited disorder that affects tubular reabsorption is suspected. It may also be used to monitor people with diagnosed aminoaciduria.

How is the test performed?

You collect all urine produced over a full 24-hour period in a labeled container provided by the laboratory. The laboratory then measures lysine and creatinine and calculates their ratio.

How do I prepare for the test?

Follow the laboratory's collection instructions carefully, including the exact start and end times. Keep the container refrigerated if instructed, record any missed collections, and tell the laboratory if you take lysine supplements because they may affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Lysine/Creatinine Ratio

Frequently asked questions

What does an elevated urine lysine-to-creatinine ratio mean?
It may mean that more lysine is being lost in the urine than expected, possibly because the kidneys are not reabsorbing it effectively. The cause can include an inherited transport disorder, kidney disease, or lysine supplementation.
Do I need to fast for this test?
Fasting is usually not required, but follow any specific instructions from your clinician or laboratory. The healthcare team should know if you take lysine supplements.
How is a 24-hour urine collection done?
Collect all urine for exactly 24 hours, following the start and end times and any refrigeration instructions provided by the laboratory. A missed or incomplete collection can make the result less reliable.
  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