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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. It helps doctors assess how well your body is using oxygen and managing energy during stress or illness.

Quick summary

["Lactate levels can indicate poor oxygen delivery or metabolic issues, especially in emergencies or chronic conditions."]

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

Key facts at a glance

LOINC
32693-4
Short code
Lactate Bld-sCnc
Synonyms
Lactate Bld-sCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Critical range
— – 4 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 It’s Done

Doctors may order this test if you have symptoms like rapid breathing, confusion, fatigue, or low blood pressure—common in conditions like heart failure, shock, or severe infections. It’s also used in monitoring patients with conditions like sepsis, stroke, or during surgery to track how well your body is handling oxygen.

What to Expect

A small blood sample is drawn from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The test is quick and doesn’t require special preparation.

What the Results Mean

Lactate levels vary based on activity, health, and medical conditions. High levels may signal poor oxygen use, while very low levels could indicate overuse of oxygen or certain metabolic disorders. Your doctor will interpret results in the context of your symptoms and overall health.

Common Causes of Abnormal Results

Elevated lactate can occur due to low oxygen (hypoxia), heart problems, infections, or severe illness. Low levels might happen in rare metabolic disorders or if your body is overproducing oxygen. Always discuss results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lactate Level

Frequently asked questions

What happens if my lactate level is high?
A high lactate level often points to conditions where your body isn’t getting enough oxygen (e.g., heart failure, shock) or where cells aren’t breaking down glucose efficiently (e.g., sepsis, diabetes). Your doctor may adjust treatments like oxygen therapy, fluids, or medications to help your body recover.
What should I do if my lactate level is low?
Low lactate can sometimes be normal, but it may also indicate rare metabolic issues or overuse of oxygen in some cases. Your doctor will review your medical history and other test results to determine if further testing or adjustments are needed.
Does fasting affect this test?
No, fasting isn’t required for this test. However, your doctor may ask you to stop certain medications or discuss recent activity levels, as these can influence results.
  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