Skip to content

Serum Lactate Concentration (Quantitative)

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

This test measures the amount of lactate, a substance produced when your body breaks down sugar for energy, in your blood serum.

Quick summary

["Lactate levels help assess how well your body is using oxygen and managing energy production, especially in critical conditions like heart or lung issues."]

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

Key facts at a glance

LOINC
34324-4
Short code
Lactate Ur-sCnc
Synonyms
Lactate Ur-sCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Critical range
— – 4 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Doctors may order this test to evaluate conditions affecting oxygen use, such as heart failure, shock, or severe infections. It’s also used in monitoring patients with metabolic disorders or during surgeries requiring close blood sugar and oxygen tracking.

What Does a High or Low Level Mean?

Elevated lactate levels often signal poor oxygen delivery to tissues (e.g., from heart problems, low blood pressure, or severe illness). Low levels may indicate overuse of oxygen or certain metabolic disorders.

Common Conditions Monitored

This test is critical in diagnosing or managing conditions like sepsis, heart attacks, or respiratory failure, where lactate buildup can be a red flag for worsening health.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The serum portion is then tested in a lab to measure lactate concentration using a specialized method.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Lactate is a key marker for tissue hypoxia (lack of oxygen) and metabolic stress. High levels can indicate severe illness, poor circulation, or organ dysfunction, prompting urgent medical attention. Conversely, very low levels may warrant investigation into conditions like overcorrection of metabolic acidosis or rare genetic disorders.

Short name

Serum Lactate

Frequently asked questions

When might I need this test?
Your doctor may recommend it if you’re critically ill, undergoing surgery, or experiencing symptoms like rapid breathing, confusion, or low blood pressure that suggest poor oxygen use.
What are the typical results interpreted as?
Results are compared to your baseline or clinical context (e.g., symptoms, other tests). Elevated lactate often triggers further evaluation for underlying causes like heart or lung disease.
Does fasting affect this test?
No, unlike glucose tests, fasting isn’t required for lactate measurement, as it reflects ongoing metabolic activity.
  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