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Serum Lactate Concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of lactate, a byproduct of energy production in your body, in your blood serum. It helps assess how well your body is using oxygen and generating energy.

Quick summary

["Lactate levels can signal potential issues with oxygen delivery or metabolism."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
27941-4
Short code
Lactate CSF-mCnc
Synonyms
Lactate CSF-mCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Critical range
— – 4 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for conditions affecting how your body uses oxygen, such as heart or lung problems, severe infections, or low blood sugar. It can also be used during surgery or critical care to monitor your body’s response to stress or illness.

What Does a High or Low Level Mean?

High lactate levels may indicate poor oxygen supply to tissues (like in shock, heart failure, or severe infections). Low levels might suggest overuse of oxygen or unusual metabolic processes, though this is less common.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The serum portion is separated and sent to a lab for measurement using a specialized method that detects lactate concentration.

What Are Common Causes?

Common causes of abnormal lactate levels include severe infections, heart or lung disease, dehydration, or conditions that restrict blood flow to tissues. Medications or certain medical treatments can also affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Lactate is a marker for tissue hypoxia (low oxygen) and metabolic stress. Elevated levels often appear early in severe illness or injury, guiding urgent treatment decisions.

Short name

Serum Lactate

Frequently asked questions

What triggers a lactate test?
A lactate test may be ordered if you have symptoms like confusion, rapid breathing, or low blood pressure, especially after trauma, surgery, or a severe illness. Your doctor might also check it during monitoring in intensive care.
How long does it take to get results?
Results are typically available within 24 hours, depending on lab processing times. Your doctor will discuss them with you during your follow-up visit.
Can lifestyle changes affect lactate levels?
While extreme exercise or fasting can temporarily raise lactate, lifestyle factors like diet or hydration are less likely to impact baseline levels unless underlying health conditions exist.
  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 16, 2026. · Read our editorial policy