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Homocysteine-to-Creatinine Ratio, Urine

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

Measures urinary homocysteine relative to creatinine, helping account for urine concentration when evaluating increased homocysteine excretion.

Quick summary

["An elevated urine ratio may indicate increased homocysteine excretion, which can occur with inherited or nutritional causes."]

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

Key facts at a glance

LOINC
22707-4
Short code
(Hcys)2/Creat Ur-sRto
Synonyms
(Hcys)2/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 homocysteine in urine and compares it with the amount of creatinine in the same sample. Creatinine is used as a reference because urine concentration can vary from one collection to another.

Why might I need this test?

A urine homocysteine-to-creatinine ratio may be used to investigate unusually high homocysteine excretion. It can be helpful when evaluating inherited disorders of homocysteine metabolism, sometimes called homocystinuria, or when monitoring treatment for such a condition.

How is the test performed?

A urine sample is collected and tested in the laboratory. The laboratory measures homocysteine and creatinine and may report the results individually, as a ratio, or both, depending on the test and collection method.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional, because a first-morning, random, or timed urine collection may be specified. If a 24-hour collection is requested, collect all urine for the full period and record the total volume. Fasting is generally not required unless instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine homocysteine/creatinine ratio

Frequently asked questions

Why is creatinine included in this urine test?
Creatinine is commonly used to help adjust the homocysteine result for variations in urine concentration. A creatinine value that is unusually high or low can affect interpretation of the ratio.
Does an elevated result mean I have homocystinuria?
No. An elevated ratio does not diagnose homocystinuria by itself. It can have nutritional, genetic, kidney-related, medication-related, or collection-related causes and should be interpreted with other tests.
How much urine is needed?
The required amount and collection method depend on the laboratory. For a timed collection, following the full collection period and volume instructions is especially important for an accurate result.
  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