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Bicarbonate Ion Concentration in Fluid (e.g., Serum or Plasma)

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 part of your body’s effort to maintain healthy pH levels.

Quick summary

["Bicarbonate helps regulate how well your body functions by keeping blood chemistry stable."]

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

Key facts at a glance

LOINC
95363-8
Short code
HCO3 p secretin stim Pnl Fld
Synonyms
HCO3 p secretin stim Pnl Fld
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 This Test Matters

Your body relies on bicarbonate to balance acids produced during normal metabolism, exercise, or digestion. Low or high levels can signal problems like kidney disease, dehydration, or metabolic disorders.

What to Expect Before the Test

No special preparation is needed unless instructed by your provider. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If testing urine or another fluid, follow your provider’s instructions for collection.

Common Conditions Affecting Results

Changes in bicarbonate can occur with conditions like chronic kidney disease, severe vomiting or diarrhea (leading to low bicarbonate), or respiratory issues (like asthma or lung disease). It may also be checked after certain medications or treatments.

What the Results Mean

Results are typically reported as a concentration value (e.g., mmol/L). Your provider will compare these numbers to your body’s usual range and discuss them with you based on your health history.

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.

Clinical Significance: Bicarbonate Levels Reflect Metabolic Health

Short name

Bicarbonate Level

Frequently asked questions

How often will I need this test?
This test may be done occasionally to monitor conditions like acid-base balance, kidney function, or metabolic disorders. Your provider will determine how often it’s needed based on your health needs.
Can I eat or drink before the test?
For blood tests, you may eat and drink normally unless your provider specifies otherwise. For urine tests, follow your provider’s instructions for timing and diet restrictions.
What if my results are out of range?
If your bicarbonate level is low, it may indicate metabolic acidosis (too much acid in your blood). If high, it could signal metabolic alkalosis (too little acid). Your provider will work with you to address any findings and adjust treatment if needed.
  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