Serum Gastric Acid (Pepsinogen I and II Ratio)
This test measures the ratio of two proteins, pepsinogen I and pepsinogen II, produced by your stomach lining. It helps assess the health of your stomach lining and may indicate conditions like atrophic gastritis or Helicobacter pylori infection.
["This test can help diagnose stomach issues by checking protein levels linked to stomach lining health."]
Key facts at a glance
- LOINC
- 55775-1
- Short code
- DAT IgA-Sp Reag RBC Ql
- Synonyms
- DAT IgA-Sp Reag RBC Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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
Why This Test Is Done
Your doctor may order this test if you have symptoms like stomach pain, nausea, vomiting, or unexplained weight loss. It may also be used to monitor conditions like chronic gastritis or to check for stomach infections. Sometimes, it’s part of a screening for conditions affecting stomach acid production.
What to Expect Before the Test
No special preparation is needed. You may have a blood sample drawn from a vein in your arm. If you’re taking medications that affect stomach acid, let your doctor know before the test.
What the Results Mean
A low pepsinogen I/II ratio often suggests stomach inflammation or infection. High levels may indicate other conditions like stomach cancer or severe atrophy. Your doctor will interpret results in the context of your symptoms and medical history.
Common Conditions This Test Helps Diagnose
This test can help diagnose conditions like Helicobacter pylori infection, atrophic gastritis (thinning of the stomach lining), or early signs of stomach cancer. It’s also useful for monitoring long-term stomach health in people with chronic conditions.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A low pepsinogen ratio can signal inflammation or infection in the stomach, which may require treatment with antibiotics or other medications. High ratios may prompt further testing for conditions like cancer or other stomach disorders. Your doctor will guide next steps based on your results and symptoms.
Short name
Gastric Acid Ratio Test
Frequently asked questions
How long does it take to get my test results?
What does a low pepsinogen I/II ratio mean?
Can I eat or drink anything before 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