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Serum or Plasma 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.

Quick summary

["Lactate helps assess how well your body is using oxygen for energy and can signal potential health concerns."]

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

Key facts at a glance

LOINC
59004-2
Short code
Lactate BS SerPl-sCnc
Synonyms
Lactate BS SerPl-sCnc
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 healthcare provider may order lactate testing to check for conditions affecting oxygen use, such as severe infections, heart problems, or low blood flow. It’s also used in emergencies like shock or severe dehydration to monitor critical situations.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. If you’re in a hospital setting, the process may be done while you’re already receiving treatment.

What the Results Mean

Higher-than-normal levels may indicate poor oxygen use, which can happen with conditions like sepsis, heart failure, or severe illness. Lower-than-normal levels might suggest certain metabolic or breathing disorders.

Common Conditions Monitored

Lactate testing is often used in critical care settings to monitor patients with suspected or confirmed conditions like severe infections, heart attacks, or low blood pressure that could impair oxygen delivery to tissues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lactate

Frequently asked questions

What causes elevated lactate levels?
Elevated lactate can result from conditions that reduce oxygen delivery to tissues (e.g., heart or lung problems), severe infections, or metabolic disorders. It may also appear during intense exercise or certain medications.
What causes low lactate levels?
Low lactate levels can occur with certain metabolic disorders, such as mitochondrial diseases, or in rare cases of overactive metabolism. It may also be seen in some genetic conditions affecting energy production.
How often is this test repeated?
The frequency depends on your condition. In critical care settings, it may be checked multiple times daily to monitor progress or response to treatment. Your provider will determine the best timing based on your situation.
  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