Bicarbonate (HCO₃⁻) concentration in serum/plasma
This test measures the amount of bicarbonate, a key chemical in your blood that helps balance acidity and alkalinity. It plays a critical role in maintaining normal pH levels, which are essential for healthy bodily functions.
["Bicarbonate helps regulate your body’s acid-base balance and supports proper organ function."]
Key facts at a glance
- LOINC
- 39460-1
- Short code
- HCO3 std BldCoA-sCnc
- Synonyms
- HCO3 std BldCoA-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 is this test done?
Your doctor may order a bicarbonate test to check for conditions affecting acid-base balance, such as metabolic acidosis or alkalosis. It can also help diagnose or monitor kidney function, diabetes, liver disease, or other metabolic disorders. Sometimes, it’s part of a broader evaluation for symptoms like fatigue, confusion, or unusual breathing patterns.
What does the test involve?
A small blood sample is taken from a vein in your arm. The sample is sent to a lab where it’s analyzed to determine the bicarbonate concentration. The test typically takes a few minutes to complete, and the results are usually ready within 24 hours.
What might abnormal results mean?
Low bicarbonate levels (acidosis) may indicate conditions like kidney disease, severe dehydration, or diabetes. High bicarbonate levels (alkalosis) could suggest overuse of antacids, vomiting, or certain kidney or metabolic disorders. Your doctor will interpret the results in the context of your overall health and symptoms.
How is the test prepared?
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a metabolic panel. Avoiding certain medications (like some blood pressure drugs) may also be advised—always follow your doctor’s instructions.
Reference range
NCBI: HCO3- 22-28 mmol/LN/A
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 is a critical buffer in blood, helping maintain homeostasis by counteracting acids produced during normal metabolism. Abnormal levels often reflect underlying metabolic or respiratory disorders, requiring prompt evaluation to prevent complications like organ damage or neurological issues.
Short name
Serum bicarbonate level
Frequently asked questions
How long does it take to get results?
Can I eat or drink before the test?
Does this test hurt?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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