Platform
Company
Immunology & Autoimmune
Review status
Currently under review
Pending specialist review and validation.
U24 Total Porphyrins is a urine test that measures the combined amount of porphyrins your body releases over a complete day. Porphyrins are natural building blocks used to make heme, a key part of hemoglobin and many enzymes. When the heme pathway is disrupted, porphyrins can accumulate and spill into urine.
This test uses a full-day collection to capture fluctuations that can occur during the day. It often serves as a screening step and may be paired with tests that separate individual porphyrin types or measure related compounds to better pinpoint the source of a problem.
Clinicians order this test when symptoms raise concern for porphyria or related conditions, such as sudden severe abdominal pain, nerve symptoms, dark urine, or skin sensitivity to sunlight. It helps detect excess porphyrin production that can occur in inherited porphyrias, liver disease, or certain toxic exposures.
Results can guide next steps, including more specific porphyrin fractionation, related urine markers, blood tests, or genetic studies. The test can also help monitor known porphyria and check response to treatment or trigger avoidance. Because medications, alcohol, hormones, and illness can alter porphyrin production, your healthcare team interprets this test alongside your history and other labs.
If your porphyrins are higher than expected, your clinician will consider your symptoms, the collection quality, and other lab findings. Elevated values can be seen in porphyrias as well as in liver inflammation, alcohol use, certain drugs, or heavy metal exposure. Follow‑up may include fractionated urinary porphyrins, urinary ALA and PBG, plasma or fecal porphyrins, and sometimes genetic testing to clarify the type and cause.
A result within the expected range is reassuring, but no single test completely rules out porphyria. If symptoms persist, your clinician may repeat testing during an active episode or use targeted studies. Let your care team know if any urine was missed, if the container was not protected from light, or if storage instructions were not followed, since these issues can affect accuracy.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
All urine over a full day should be collected, with the container protected from light and stored as instructed. Missing portions, light exposure, or improper storage can lower measured porphyrins and lead to misleading results.
Barbiturates, rifampin, anticonvulsants, estrogens, alcohol, and tobacco can increase porphyrin production or change excretion. Share all prescriptions, over‑the‑counter drugs, supplements, and recreational substances with your clinician.
Porphyrin levels can fluctuate with attacks or skin flares. Collecting during or soon after symptoms may improve detection compared with symptom‑free periods and can influence whether additional tests are needed.
Liver disease can raise urinary porphyrins, while reduced kidney function can alter excretion patterns. These conditions influence interpretation and may prompt complementary blood or stool testing.
Crash dieting, fasting, or very low carbohydrate intake can precipitate attacks in susceptible individuals and may alter porphyrin levels. Discuss diet changes with your care team before testing.
Pregnancy, adolescence, and older age can affect hormone balance and heme metabolism. Interpretation may differ in these settings, and collection logistics may require extra planning or support.
References