Phbldv
This test measures the acidity or alkalinity of your venous blood sample, helping doctors assess your body's acid-base balance.
{"Measures the acid-base balance in your venous blood","Normal pH range is approximately 7.35-7.45","Helps diagnose conditions like acidosis or alkalosis","Often used to evaluate respiratory and metabolic disorders","Requires a blood sample drawn from a vein"}
Key facts at a glance
- LOINC
- 2746-6
- Short code
- pH BldV
- Synonyms
- pH BldV
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- not specified
- Ref low
- 7.32
- Ref high
- 7.43
- Critical range
- 7.2 not specified – 7.6 not specified
- 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
What is this test?
The venous blood pH test measures the concentration of hydrogen ions in your blood, indicating how acidic or alkaline your blood is. This test is part of a larger set of tests called arterial blood gas (ABG) analysis, though venous samples are sometimes used when arterial sampling is not necessary. The pH scale ranges from 0 to 14, with 7 being neutral. Your blood should normally be slightly alkaline, with a pH between 7.35 and 7.45.
How is the test performed?
A healthcare professional will draw a blood sample from a vein in your arm using a needle. The sample is then placed in a special tube and sent to a laboratory for analysis. The test is relatively quick and may be part of a routine metabolic panel or ordered specifically when your doctor suspects an acid-base imbalance.
Why might I need this test?
Your doctor may order this test if you have symptoms such as difficulty breathing, confusion, nausea, or fatigue. It is commonly used to monitor patients with kidney disease, lung disease, diabetes, or those receiving certain treatments that affect acid-base balance. It may also be ordered during critical illness or before/after certain surgeries.
Reference range
7.32-7.43not specified
No special preparation required; collect anaerobically and analyze promptly
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Is the test painful?
What do abnormal results mean?
How often will I need this test?
Sources
- 1MedlinePlus - Blood pHSource
- 2
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 16, 2026. · Read our editorial policy