Peritoneal Fluid pH Test
This test measures the acidity level, also called the pH, of fluid taken from your abdominal cavity, helping your doctor find out whether an infection, inflammation, or another condition is affecting your abdomen.
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Key facts at a glance
- LOINC
- 68459-7
- Short code
- pH Prt Strip
- Synonyms
- pH Prt Strip
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- not specified
- Ref low
- 7.35
- Ref high
- 7.45
- Critical range
- 7.2 not specified – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- test-strip
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
The peritoneal fluid pH test measures how acidic or alkaline the fluid in your abdominal cavity is. Peritoneal fluid is a small amount of liquid that sits between the layers of tissue that line the inside of your abdomen and cover your abdominal organs. The test uses a special test strip (similar to pH paper) to determine the pH level quickly.
Why is this test done?
Your doctor may order this test if you have symptoms suggesting a problem in your abdomen, such as severe abdominal pain, fever, or signs of infection. The peritoneal fluid pH test is particularly useful for diagnosing peritonitis (inflammation of the peritoneum), which is often caused by bacterial infection. It can also help identify bowel perforation or other conditions that affect the abdominal cavity.
How is the sample collected?
The peritoneal fluid is collected through a procedure called paracentesis (also known as an abdominal tap). During this procedure, a doctor numbs a small area of your abdomen and inserts a thin needle to withdraw fluid from the abdominal cavity. The fluid is then tested immediately using a pH test strip. You may feel some pressure or discomfort during the procedure, but it is generally well-tolerated.
Understanding your results
Normal peritoneal fluid typically has a pH of approximately 7.6, which is slightly alkaline. A pH value lower than 7.2 is considered abnormal and may indicate the presence of infection, inflammation, or bowel perforation. Your doctor will interpret your results along with other clinical findings to determine the appropriate treatment.
Reference range
7.35-7.45not specified
None; sample collected by paracentesis
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings2
Short name
PF-pH
Frequently asked questions
Is the peritoneal fluid pH test painful?
How long does it take to get results?
What can affect my peritoneal fluid pH results?
Are there any risks associated with this test?
Sources
- 1
- 2
- 3
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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