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Serum/plasma 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 carbohydrates for energy, in your blood.

Quick summary

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

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

Key facts at a glance

LOINC
68911-7
Short code
Lactate p Exc SerPl-mCnc
Synonyms
Lactate p Exc 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 This Test Is Done

Doctors may order a lactate test to check for conditions like low blood oxygen (hypoxia), severe infections, heart or lung problems, or metabolic disorders. It can also help evaluate symptoms like dizziness, confusion, or rapid breathing that might indicate low blood sugar or other emergencies.

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 fasting, follow your doctor’s instructions. Avoid strenuous activity before testing if advised.

What the Test Results Mean

Lactate levels can vary based on activity, diet, and health status. High levels may signal conditions like sepsis, heart failure, or severe dehydration. Low levels could indicate poor circulation, low blood sugar, or certain metabolic issues. Your doctor will interpret results in the context of your overall health.

Common Conditions Monitored

Lactate testing is often used in emergencies, like shock or severe infections, to monitor how well your body is handling oxygen. It may also be checked during surgeries or critical care to track recovery.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Lactate as a Biomarker

Short name

Lactate Level

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), extreme stress (like severe infections), or metabolic disturbances. It’s also a marker for poor tissue perfusion, such as in shock or sepsis.
What causes low lactate levels?
Low lactate levels may occur in cases of poor circulation, low blood sugar (hypoglycemia), or certain genetic or metabolic disorders. Rarely, it can be seen in healthy individuals during rest or mild exercise.
How often is this test repeated?
Your doctor may repeat the test if you’re in a critical condition (e.g., during surgery or illness) or if symptoms persist. Results are often checked closely in hospitals or clinics for ongoing monitoring.
  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