Skip to content

Hydroxylysine/Creatinine, Urine — Mass Ratio

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

A urine test that measures hydroxylysine relative to creatinine, providing a normalized estimate of urinary hydroxylysine excretion.

Quick summary

["This specialized urine test can help evaluate collagen and bone metabolism."]

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

Key facts at a glance

LOINC
30050-9
Short code
OH-Lysine/Creat Ur-Rto
Synonyms
OH-Lysine/Creat 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?

Hydroxylysine is a modified amino acid found in collagen, the main structural protein in bones, skin, tendons, and other connective tissues. This test measures urinary hydroxylysine relative to creatinine, a waste product used to account for variations in urine concentration.

Why might I need this test?

This specialized test may be ordered to evaluate collagen breakdown or bone metabolism. It is sometimes used in the assessment of skeletal disorders, bone growth, fracture healing, or conditions that affect connective tissue.

How is the test performed?

A urine specimen is collected and analyzed for hydroxylysine and creatinine. The laboratory then calculates the amount of hydroxylysine relative to the amount of creatinine in the sample.

How do I prepare for the test?

Follow the collection instructions provided by your clinician or laboratory. If a timed or 24-hour urine collection is requested, collect all urine for the specified period; otherwise, follow the laboratory's instructions for a routine urine sample. Do not stop medications without medical advice.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine hydroxylysine-to-creatinine ratio

Frequently asked questions

What does the hydroxylysine-to-creatinine ratio measure?
It measures the amount of hydroxylysine in urine relative to creatinine. Creatinine helps adjust the result for differences in urine concentration.
Why is hydroxylysine tested in urine?
Urine hydroxylysine can provide information about the breakdown of collagen, a major protein in bones and other connective tissues.
Does an abnormal result mean I have a bone disease?
Not necessarily. High or low results may have several causes and must be interpreted alongside symptoms, medical history, other tests, and medications by a healthcare professional.
  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