Urine Homocysteine-to-Free Creatinine Ratio
This urine test compares homocysteine with creatinine, helping account for differences in urine concentration.
["The ratio can help identify unusually high urinary homocysteine when evaluating possible disorders of homocysteine metabolism."]
Key facts at a glance
- LOINC
- 48115-0
- Short code
- Hcys.free/Creat Ur-sRto
- Synonyms
- Hcys.free/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 relative to the amount of creatinine in a urine sample. Creatinine is used as a reference to help account for variations in how concentrated the urine is.
Why might I need this test?
It may be used to evaluate suspected homocystinuria or other inherited or acquired conditions that affect homocysteine metabolism. It is often interpreted along with blood homocysteine, vitamin status, and other laboratory results.
How is the test performed?
A urine specimen is collected and tested in the laboratory. The laboratory measures urinary homocysteine and creatinine and then calculates their ratio.
How do I prepare for the test?
Follow the collection instructions provided by the laboratory, including whether a first-morning or timed urine sample is required. Complete the entire collection if a timed sample is requested, and ask the laboratory about diet or medication restrictions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated ratio may indicate increased urinary excretion of homocysteine, which can occur with inherited disorders of homocysteine metabolism and may also be associated with vitamin B12, folate, or B6 deficiency. Results should be interpreted by a clinician together with blood tests and clinical findings because urine concentration, diet, supplements, medications, and kidney function can affect the result.
Short name
Urine homocysteine/creatinine ratio
Frequently asked questions
What does the homocysteine-to-creatinine ratio measure?
Is this the same as a blood homocysteine test?
What could cause an abnormal result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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