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Porphyrins/Creatinine Ratio, Urine

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

A urine test that measures porphyrins relative to creatinine, helping evaluate possible porphyrin disorders when kidney function or urine concentration may affect results.

Quick summary

["This test can help identify increased porphyrin excretion, but results must be interpreted with symptoms and other laboratory findings."]

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

Key facts at a glance

LOINC
108517-4
Short code
Porphyrins/Creat Msmt Ur
Synonyms
Porphyrins/Creat Msmt 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 test measures porphyrins in urine and compares the amount with urine creatinine. Porphyrins are natural building blocks related to heme, and the ratio helps account for how concentrated or dilute the urine sample is.

Why might I need this test?

It may be ordered when symptoms suggest a porphyria, a group of inherited or acquired conditions affecting heme production. Doctors may also use it when investigating unexplained abdominal, neurologic, skin, or light-related symptoms.

How is the test performed?

A urine sample is analyzed in the laboratory to measure porphyrins and creatinine. The laboratory then calculates the porphyrin-to-creatinine ratio. This is usually a single urine collection unless your clinician requests a different collection period.

How do I prepare for the test?

Follow your clinician's collection instructions and provide a fresh urine specimen in the specified container. Unless instructed otherwise, do not empty your bladder shortly before collection. Fasting is generally not required, but tell the laboratory about medicines, supplements, and recent alcohol use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine porphyrin-to-creatinine ratio

Frequently asked questions

Is this the same as a 24-hour urine test?
Not necessarily. It may be performed on a single urine specimen, although a timed collection can be used if your clinician specifically requests it.
Why is creatinine included?
Creatinine helps show how concentrated the urine is. Including it makes the porphyrin result easier to compare across samples, although kidney function and hydration can still affect interpretation.
Do abnormal results confirm a porphyria?
No. An elevated result can have several causes and must be interpreted with symptoms, medication history, urine findings, and other blood or genetic tests.
  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