Urinary Hippuric Acid (24-Hour Collection) – Mass Concentration
This test measures the total amount of hippuric acid excreted in your urine over a 24-hour period. Hippuric acid is a breakdown product of benzoic acid, which your body forms from dietary sources and certain medications.
["This test helps assess how well your liver and kidneys process certain substances in your diet and medications."]
Key facts at a glance
- LOINC
- 25161-1
- Short code
- Hippurate Cry #/area UrnS HPF
- Synonyms
- Hippurate Cry #/area UrnS HPF
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 7.2
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light-hpf
- 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
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if they suspect issues related to how your body processes benzoic acid, such as in conditions like phenylketonuria (a rare genetic disorder) or to monitor medication metabolism. It can also be part of evaluating liver function or kidney health indirectly.
What to Expect Before the Test
For this test, you’ll collect all of your urine over a full 24-hour period. Typically, you’ll start by emptying your bladder at the beginning of the collection period (often at home) and then collect every urine void afterward in a container. At the end of 24 hours, you’ll return the sample to your lab. Follow your provider’s instructions carefully to ensure accuracy.
What Happens During the Test
The collected urine sample is analyzed in a lab to measure the total hippuric acid content. The results are expressed as the total amount excreted in milligrams (mg) over the 24-hour period. The lab may also calculate the concentration per unit of urine volume if needed.
What the Results Mean
Hippuric acid levels can vary based on diet, medications, and individual metabolism. Abnormally high or low levels may indicate underlying health concerns, such as metabolic disorders or liver/kidney issues, but interpretation depends on clinical context and other test results.
Reference range
NCBI: Uric Acid Male 3.5-7.2 mg/dL; Female 2.5-6.8 mg/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
24-Hour Urine Hippuric Acid
Frequently asked questions
What causes elevated hippuric acid levels?
What causes low hippuric acid levels?
How often should I get this test?
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 17, 2026. · Read our editorial policy