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Serum Gastric Acid (Lowering) Quantification via Qualitative Probe (Screening)

Published: August 9, 2026Updated: August 16, 2026

This test measures the presence of gastric acid in your blood, often checked to assess stomach function or acid-related conditions.

Quick summary

["A screening for potential acid-related issues in your digestive system."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
57905-2
Short code
Hgb sp1 Stl gastro lower Ql IA
Synonyms
Hgb sp1 Stl gastro lower Ql IA
Category
hematology
Sample
stool
Container
Clean container
Units
N/A
Ref low
10
Ref high
40
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
84484
SNOMED
302774002
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

What This Test Measures

This test detects the concentration of gastric acid in your serum. Gastric acid is a key component of stomach digestion, and its presence can be evaluated to identify abnormalities in acid production or absorption.

Why It Might Be Ordered

Your healthcare provider may order this test if you have symptoms like heartburn, nausea, or unexplained weight loss, or if they suspect conditions like gastroesophageal reflux disease (GERD), ulcers, or other digestive disorders.

Common Reasons for Testing

It may also be used as part of a broader evaluation for conditions affecting stomach function, such as Zollinger-Ellison syndrome or after treatment for acid-related conditions to monitor effectiveness.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The sample is processed to separate serum, which is then analyzed to detect gastric acid presence.

Reference range

Adult: 10-40 U/LN/A

Specimen: stool

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Gastric Acid Screening (Serum)

Frequently asked questions

How is this test used in clinical practice?
This screening test helps identify potential abnormalities in gastric acid levels, guiding further diagnostic steps or treatment plans for conditions affecting digestion and stomach function.
What does a positive or abnormal result mean?
An abnormal result may indicate an excess or deficiency of gastric acid, which could signal underlying digestive issues. Results will be interpreted by your healthcare provider in the context of your symptoms and medical history.
Can this test be done at home?
No, this test requires a medical professional to collect the blood sample in a clinical setting.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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 16, 2026. · Read our editorial policy