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Serum Bicarbonate (Mass Concentration)

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

This test measures the amount of bicarbonate, a key chemical in your blood that helps regulate acidity (pH). It’s part of your body’s effort to keep your blood chemistry balanced.

Quick summary

["Bicarbonate helps balance acidity in your blood and is crucial for normal bodily functions."]

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

Key facts at a glance

LOINC
111961-9
Short code
Site SB Endscpy
Synonyms
Site SB Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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 Does This Test Measure?

Bicarbonate is a vital buffer in your blood, helping to maintain a stable pH level. When levels are too high or too low, it can signal underlying health issues, such as metabolic conditions or kidney problems.

Why Is This Test Done?

Your doctor may order this test if you have symptoms like fatigue, confusion, rapid breathing, or irregular heartbeat. It’s also used to diagnose or monitor conditions like metabolic acidosis or alkalosis, kidney disease, or diabetes.

How Is the Test Performed?

A small blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure bicarbonate levels.

What Are Common Results?

Results are typically reported in milliequivalents per liter (mEq/L). While exact reference ranges vary by lab, abnormal results may indicate imbalances that need further medical evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal bicarbonate levels can signal serious conditions like diabetic ketoacidosis, kidney failure, or respiratory disorders. Your doctor will use these results alongside other tests and symptoms to guide treatment decisions.

Short name

Bicarbonate Level

Frequently asked questions

What causes low bicarbonate levels?
Low bicarbonate levels (metabolic acidosis) can occur due to conditions like kidney disease, severe diarrhea, or diabetic ketoacidosis. It may also result from certain medications or metabolic disorders.
What causes high bicarbonate levels?
High bicarbonate levels (metabolic alkalosis) can happen with prolonged vomiting, excessive use of antacids, or conditions like kidney disease or heart failure. Overuse of diuretics or certain breathing disorders may also contribute.
Do I need to prepare for this test?
No special preparation is usually needed, but avoid heavy meals before the test. If you’re on medications that affect blood chemistry, let your doctor know to ensure accurate results.
  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