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Neutrophil-to-Lymphocyte Ratio (NLR) in Whole Blood

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

This test measures the ratio of your body’s white blood cells—specifically neutrophils and lymphocytes—to help assess your immune response and overall health.

Quick summary

["The NLR can provide clues about inflammation or infection levels in your body."]

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

Key facts at a glance

LOINC
85779-7
Short code
N men DNA Bld Pos Ql NAA+n-prb
Synonyms
N men DNA Bld Pos Ql NAA+n-prb
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-probe-amp-tar
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

What Is Neutrophil-to-Lymphocyte Ratio (NLR)?

Neutrophils and lymphocytes are types of white blood cells that play key roles in fighting infections and inflammation. The NLR compares their counts, which can shift depending on your health status. For example, higher NLR may suggest inflammation or infection, while lower NLR might indicate a calmer immune response.

Why Might You Need This Test?

Doctors may order an NLR test to monitor conditions like chronic inflammation, infections, autoimmune diseases, or to evaluate response to treatment. It’s also sometimes used in cancer care or after surgery to track recovery.

How Is the Test Performed?

A small blood sample is drawn from a vein, typically in your arm. The blood is analyzed to count neutrophils and lymphocytes, then the ratio is calculated. No special preparation is needed, but fasting may not affect this test.

What Do the Results Mean?

Results are not given as a single reference range because they vary by individual and clinical context. Instead, doctors compare your NLR to your own baseline or to other test results to interpret whether it’s elevated or low. For example, a higher NLR might signal inflammation, while a lower NLR could suggest a less active immune response.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: NLR as a Marker of Immune and Inflammatory Status

Short name

NLR (Whole Blood)

Frequently asked questions

How often will I need this test?
The frequency depends on your medical condition and treatment plan. Some patients get NLR tests monthly or as needed to monitor progress, while others may only need it once or twice a year.
What are typical reference ranges for NLR?
There isn’t a single standard reference range for NLR because it changes based on your health, age, and medical history. Doctors use it more as a relative measure compared to your own results or other tests.
Can I eat or drink before this test?
No special diet or fasting is required for this blood test, so you can eat and drink normally before your appointment.
  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