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Bicarbonate Ion Concentration (Serum)

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

This test measures the amount of bicarbonate, a key chemical in your blood that helps regulate your body’s acid-base balance.

Quick summary

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

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

Key facts at a glance

LOINC
94010-6
Short code
HCO3 2h p Vaso SerPl-sCnc
Synonyms
HCO3 2h p Vaso SerPl-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
22
Ref high
28
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is This Test Done?

Your doctor may order this test to check for conditions affecting how well your body maintains acid-base balance, such as metabolic acidosis or alkalosis. It can also help diagnose or monitor kidney function, diabetes, or other metabolic disorders.

What Does a Low or High Bicarbonate Level Mean?

Low bicarbonate levels may indicate too much acid in your blood (metabolic acidosis), which can happen from conditions like kidney disease, severe diarrhea, or diabetic ketoacidosis. High levels may suggest too little acid (metabolic alkalosis), often seen in conditions like vomiting, excessive antacid use, or certain kidney disorders.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw if your doctor specifies. Bring any medications or supplements you’re taking to discuss with your healthcare provider.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The blood sample will be sent to a lab to measure bicarbonate levels using a specialized method.

Reference range

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

Specimen: serum

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.

◆Associated findings1

Short name

Bicarbonate (Serum)

Frequently asked questions

How long will the results take to return?
Results are typically available within 24 to 48 hours, depending on your lab’s processing schedule. Your doctor will discuss the results with you during your follow-up visit.
Can I eat or drink anything before the test?
Unless instructed otherwise, you can eat and drink normally before this test. Some tests may require fasting, so always follow your doctor’s specific instructions.
What are the possible side effects of the blood draw?
The most common side effect is mild bruising, swelling, or soreness at the injection site. Rarely, you might feel lightheaded or dizzy during the draw, especially if you’re dehydrated.
  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