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Serum or Plasma Lactate Concentration

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

This test measures the amount of lactate, a substance produced when your body breaks down carbohydrates for energy, especially during times of low oxygen (like exercise or illness).

Quick summary

["Lactate helps assess how well your body is using oxygen and managing energy."]

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

Key facts at a glance

LOINC
57365-9
Short code
Lactate 1.5h p chal SerPl-mCnc
Synonyms
Lactate 1.5h p chal SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Critical range
— – 4 N/A
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

Why Is This Test Done?

Your doctor may order this test to check for conditions affecting how your body produces or uses energy, such as heart or lung problems, infections, or metabolic disorders. It can also help monitor conditions like shock, sepsis, or during surgery.

When Might You Need This Test?

You might need this test if you have symptoms like rapid breathing, confusion, weakness, or if you’re recovering from surgery, an injury, or a severe illness. Doctors also use it during critical care situations.

What to Expect Before the Test

No special preparation is needed. Blood is drawn from a vein in your arm, similar to other blood tests. If you’re on oxygen or have a breathing tube, your doctor may adjust how the test is done.

What Happens During the Test?

A healthcare provider will clean the area, insert a small needle into your vein, and collect a blood sample. The sample is then sent to a lab to measure lactate levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High lactate levels can indicate poor oxygen delivery to tissues (e.g., heart failure, severe infections), or metabolic issues like diabetes or liver problems. Low levels may suggest overuse of oxygen or certain medications. Always discuss results with your doctor.

Short name

Lactate Level

Frequently asked questions

What Does a High Lactate Level Mean?
A high lactate level may signal that your body isn’t getting enough oxygen, which can happen with heart problems, infections, or dehydration. Your doctor will review your symptoms and other test results to understand the cause.
What Does a Low Lactate Level Mean?
Low lactate levels might occur in certain medical conditions or after certain treatments, but they can also be normal in some situations. Your doctor will consider your overall health and other test results to interpret the result.
How Often Can I Expect This Test?
This test may be done once or multiple times depending on your health condition, treatment plan, or recovery status. Your doctor will let you know if repeat testing is needed.
  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