Skip to content

Peritoneal Fluid Albumin Test

Published: July 31, 2026Updated: August 17, 2026

This test measures the amount of albumin protein in peritoneal (abdominal) fluid to help determine the cause of fluid accumulation in the abdomen, often together with a blood albumin test to guide your doctor's diagnosis.

Quick summary

{"Albumin in peritoneal fluid helps doctors determine why fluid has accumulated in the abdomen","Results are often compared with blood albumin levels (SAAG) to distinguish between different causes","High albumin in peritoneal fluid may indicate conditions like cirrhosis, heart failure, or cancer"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
1749-1
Short code
ALB PF
Synonyms
Albumin Prt-mCnc
Category
chemistry
Sample
serum
Container
Sterile red-top or gold-top serum separator tube (SST) for simultaneous serum collection; sterile plastic container for peritoneal fluid
Units
not specified
Ref low
1
Ref high
2.5
Critical range
1.5 not specified – —
Fasting
false
Population
adult
Sex
all
Age range
≥ 18 years
Method
Bromocresol green (BCG) or Bromocresol purple (BCP) colorimetric assay
CPT
82042
SNOMED
314448003
Specimen volume
Peritoneal fluid: 2-5 mL; paired serum: 1-2 mL
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 72 hours; Frozen (-20°C): 2 weeks for batch analysis
Hemolysis max
50
Lipemia max
100
Icterus max
20
TAT
4–24 hours
Order
routine

What is this test?

The Peritoneal Fluid Albumin test measures the concentration of albumin, a protein produced by the liver, in fluid collected from the abdominal cavity (ascites or peritoneal fluid). It is typically performed along with a serum albumin blood test to calculate the Serum-Ascites Albumin Gradient (SAAG), which helps your doctor identify the underlying cause of abdominal fluid buildup and choose the most appropriate treatment.

How is the sample collected?

Peritoneal fluid is collected through a procedure called paracentesis, in which a thin needle is inserted into the abdominal cavity under local anesthesia to withdraw a small amount of fluid. You may feel brief pressure or mild discomfort during the procedure. A blood sample from a vein in your arm is also taken so serum albumin levels can be compared with the fluid results.

Why is this test performed?

This test helps your doctor determine the cause of ascites, which is the accumulation of fluid in the abdomen. By comparing albumin levels in the peritoneal fluid with levels in your blood, physicians can distinguish between different conditions causing the fluid buildup, such as liver disease, heart failure, kidney disease, infection, or cancer, and direct you to the right care.

Reference range

Not establishednot specified

Specimen: serum

No special preparation; specimen obtained by paracentesis (concurrent serum albumin recommended for SAAG)

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

SAAG ≥1.1 g/dL indicates portal hypertension (high blood pressure in the liver veins), commonly seen in cirrhosis, heart failure, or Budd-Chiari syndrome. SAAG <1.1 g/dL suggests non-portal hypertensive causes like cancer, infection, pancreatitis, or kidney disease. The albumin level in peritoneal fluid helps guide further diagnostic tests and treatment decisions.

Frequently asked questions

Does the test require fasting?
No fasting is typically required for this test, and you can usually eat and drink normally beforehand. However, always follow your doctor's specific instructions, since additional tests ordered at the same time may have different preparation requirements.
Are there any risks with paracentesis?
Minor risks include bleeding, infection, or injury to nearby organs, and some people may feel lightheaded or have mild pain at the needle site. These complications are rare when the procedure is performed by experienced healthcare providers using sterile technique.
How long does it take to get results?
Results are usually available within 1-2 days, depending on the laboratory and whether additional studies are performed on the fluid. Your doctor will contact you to discuss the results and explain what they mean for your care plan.
What do high albumin levels mean?
High peritoneal fluid albumin, corresponding to a SAAG ≥1.1, typically indicates portal hypertension, most often caused by liver cirrhosis or heart failure. Low levels suggest other causes, such as infection, inflammation, or cancer, and your doctor will interpret the result together with your symptoms and medical history.
  1. 1
    Mayo Clinic - AscitesSource
  2. 2
    MedlinePlus - ParacentesisSource
  3. 3
    American College of Gastroenterology - SAAGSource

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 17, 2026. · Read our editorial policy