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Bicarbonate concentration in whole blood (measured as mass concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of bicarbonate, a key chemical in your blood that helps balance acidity and alkalinity. It’s often checked alongside other blood chemistry tests.

Quick summary

["Bicarbonate helps regulate your body’s pH and supports normal breathing and metabolism."]

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

Key facts at a glance

LOINC
19230-2
Short code
HCO3 std BldA-sCnc
Synonyms
HCO3 std BldA-sCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
22
Ref high
28
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Done

Your doctor may order this test if you have symptoms like shortness of breath, fatigue, confusion, or signs of acid-base imbalance. It could also be part of routine monitoring for conditions like kidney disease, diabetes, or metabolic disorders.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for a few hours if your blood is drawn early in the morning. Avoid strenuous activity before testing.

How the Test Works

A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab where it’s analyzed to measure bicarbonate levels using a specialized method.

What the Results Mean

Results are compared to standard reference ranges, but exact values can vary by lab. Low bicarbonate may indicate metabolic acidosis, while high levels could suggest metabolic alkalosis or other conditions.

Reference range

NCBI: HCO3- 22-28 mmol/LN/A

Specimen: whole-blood

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Bicarbonate Levels and Health

Short name

Bicarbonate (HCO₃⁻) Level

Frequently asked questions

How does bicarbonate relate to my overall health?
Bicarbonate is crucial for maintaining your body’s acid-base balance. Abnormal levels can signal underlying issues like kidney problems, heart conditions, or severe infections. Your doctor will discuss results in the context of your symptoms and medical history.
What causes low bicarbonate levels?
Low bicarbonate can result from conditions like severe dehydration, kidney failure, or certain medications. It may also appear in metabolic acidosis, where the body produces too much acid or loses too much bicarbonate.
What causes high bicarbonate levels?
High bicarbonate levels can occur with conditions like vomiting, diarrhea, or excessive use of antacids. It may also be seen in metabolic alkalosis, where the body retains too much bicarbonate or loses too much acid.
  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 17, 2026. · Read our editorial policy