Bicarbonate Ion Concentration in Plasma
This test measures the amount of bicarbonate (HCO₃⁻), 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.
["Bicarbonate helps maintain your body’s pH balance and supports normal breathing and kidney function."]
Key facts at a glance
- LOINC
- 54361-1
- Short code
- HCO3 Plr-sCnc
- Synonyms
- HCO3 Plr-sCnc
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 22
- Ref high
- 28
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may order this test if they suspect conditions like metabolic acidosis (too much acid in your blood) or alkalosis (too little acid), especially after symptoms like nausea, confusion, or rapid breathing. It’s also checked in cases of kidney disease, heart failure, or after certain medications or injuries.
What to Expect Before the Test
No special preparation is needed for this test. You’ll likely have a small needle inserted into your arm to draw a blood sample. The process is quick and usually painless. If you’re on blood thinners, let your doctor know before the test.
What the Results Mean
Results are compared to standard ranges for healthy adults. Low bicarbonate levels may indicate metabolic acidosis, while high levels could suggest metabolic alkalosis. Your doctor will discuss these results in the context of your overall health and symptoms.
Common Conditions Affecting Bicarbonate Levels
Conditions like severe dehydration, kidney problems, or certain medications (e.g., diuretics) can alter bicarbonate levels. Chronic respiratory issues (like COPD) may also impact it, as your lungs adjust acidity differently.
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.
Bicarbonate plays a critical role in maintaining your body’s acid-base balance. Low levels can lead to fatigue, muscle cramps, or even coma in severe cases. High levels may cause symptoms like confusion, muscle spasms, or irregular heartbeat. Always follow your doctor’s guidance based on your results.
Short name
Plasma Bicarbonate Level
Frequently asked questions
What causes low bicarbonate levels?
What causes high bicarbonate levels?
Does diet affect bicarbonate levels?
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