Serum Lactate Level (Fasted Blood Draw)
This test measures the amount of lactate, a byproduct of energy production in your body, in your blood. It helps doctors assess how well your body is using oxygen and managing energy.
["Lactate levels can indicate how efficiently your body is handling oxygen and energy, especially during illness or exercise."]
Key facts at a glance
- LOINC
- 27976-0
- Short code
- Lactate p fast Bld-mCnc
- Synonyms
- Lactate p fast Bld-mCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 4 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- 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 this test if you have symptoms like rapid breathing, confusion, or fatigue, which could signal low oxygen levels or metabolic issues. It’s also used in monitoring conditions like heart attacks, severe infections, or during surgery to check for complications.
What to Expect Before the Test
You’ll likely need to fast for 8–12 hours before the test. Bring your doctor’s instructions and wear comfortable clothing. The blood draw is quick but may cause slight discomfort at the site.
What Happens During the Test?
A healthcare provider will insert a small needle into a vein in your arm to draw blood. You may feel a brief pinch, but the process usually takes less than 5 minutes. The blood is then sent to a lab for analysis.
What Are Normal Results?
There are no standard reference ranges provided here since they vary by lab and patient factors. Your results will be compared to your specific lab’s guidelines and discussed with your doctor.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High lactate levels may signal conditions like shock, severe infections, or poor oxygen flow to tissues. Low levels can occur in rare cases of overactive metabolism or certain medications. Your doctor will interpret results in the context of your health and symptoms.
Short name
Lactate
Frequently asked questions
Why did my doctor ask for this test?
What does a high or low lactate level mean?
Do I need to prepare differently if I’m pregnant?
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 16, 2026. · Read our editorial policy