Porphobilinogen/Creatinine Ratio, Urine
Measures urine porphobilinogen relative to creatinine, helping evaluate for acute porphyria while reducing the effect of urine concentration.
["An elevated result may support the diagnosis of an acute porphyria, particularly when compatible symptoms are present."]
Key facts at a glance
- LOINC
- 13797-6
- Short code
- PBG/Creat Ur
- Synonyms
- PBG/Creat Ur
- 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 urine test measures porphobilinogen, a substance produced during heme production, relative to urine creatinine. The ratio helps account for how concentrated or dilute the urine sample is.
Why might I need this test?
It may be used to evaluate suspected acute porphyria, especially during an episode involving severe abdominal pain, nausea, weakness, confusion, or rapid heartbeat. Other causes of these symptoms are common, so an abnormal result must be interpreted with the overall clinical picture.
How is the test performed?
A urine specimen is collected and tested in the laboratory. The laboratory measures porphobilinogen and compares it with the amount of creatinine in the same sample to report a ratio.
How do I prepare for the test?
Follow your clinician or laboratory's urine-collection instructions, including any specified collection time. Tell the laboratory if you are having an acute attack because collection timing can affect interpretation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated porphobilinogen-to-creatinine ratio may indicate increased porphyrin production, as can occur in acute porphyrias. Results are most useful when obtained during symptoms and interpreted alongside the medical evaluation. A properly collected normal result may make an acute porphyria less likely, but delayed or incomplete collection can affect reliability.
Short name
Urine Porphobilinogen/Creatinine Ratio
Frequently asked questions
What does the urine porphobilinogen-to-creatinine ratio measure?
Which symptoms may lead a clinician to order this test?
Does an abnormal result confirm acute porphyria?
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