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Lactate (Serum or Plasma) 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. It can help assess how well your body is using oxygen and how efficiently your organs are working.

Quick summary

["Lactate levels can signal poor oxygen delivery or metabolic issues, often seen in emergencies like heart attacks or infections."]

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

Key facts at a glance

LOINC
74896-2
Short code
Lactate Stl-sCnt
Synonyms
Lactate Stl-sCnt
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Critical range
— – 4 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why It’s Done

Doctors 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’s also used in monitoring patients with critical illnesses like sepsis or heart attacks.

What to Expect

A blood sample is taken from a vein in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort afterward. The test is quick and done in a lab.

Normal vs. Abnormal Results

Lactate levels vary by age, health, and activity level. High levels may indicate poor oxygen flow or metabolic stress, while low levels might suggest overuse of carbohydrates or certain medications.

Common Conditions Linked to Results

Elevated lactate can signal conditions like heart failure, severe infections, or low blood oxygen. Low levels might be seen in people who rely heavily on carbohydrates for energy or those taking specific medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Lactate testing is critical in emergency settings to guide treatment for conditions like shock, sepsis, or acute heart or lung problems. It helps doctors adjust oxygen therapy, fluids, or other interventions quickly.

Short name

Lactate Level

Frequently asked questions

When might I need this test?
You may need this test if you’re in the hospital for a serious illness, have symptoms like dizziness, rapid breathing, or confusion, or if your doctor suspects poor oxygen use in your body.
What does a high lactate level mean?
A high lactate level often means your body isn’t getting enough oxygen, which can happen with heart or lung issues, infections, or severe dehydration. Your doctor will work with your test results to find the cause and treat it.
Can lifestyle changes affect this test?
Yes, exercise, diet, and hydration can influence lactate levels. Avoiding strenuous activity before the test and staying well-hydrated can help give more accurate 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