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

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

This test measures the ratio of your white blood cells’ neutrophils to lymphocytes, a simple blood check often used to assess inflammation or infection.

Quick summary

["NLR helps doctors gauge immune response and possible infections or inflammatory conditions."]

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

Key facts at a glance

LOINC
93388-7
Short code
N men DNA Bld Pos Ql NAA+probe
Synonyms
N men DNA Bld Pos Ql NAA+probe
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
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 two types of white blood cells that fight infection. NLR compares their counts to identify shifts that may signal health issues, such as infections, chronic inflammation, or even certain cancers.

Why Is This Test Done?

Doctors may order NLR testing to monitor conditions like infections, autoimmune diseases, or after surgeries to check for complications. It’s also sometimes used in cancer care to track response to treatment.

How Is the Test Performed?

A blood sample is drawn from a vein, typically in your arm. The lab uses an immunoassay method to measure the counts of neutrophils and lymphocytes, then calculates the ratio.

What Does a High or Low NLR Mean?

A high NLR often suggests inflammation, infection, or stress on the body. A low NLR might indicate immune suppression or certain immune-related conditions, though results depend on clinical context.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: NLR’s Role in Diagnosis and Monitoring

Short name

NLR (Whole Blood)

Frequently asked questions

How often will I need this test?
NLR testing frequency depends on your health condition. Some patients get it monthly or as needed during treatment, while others may only need it occasionally for monitoring.
What do my results mean if I’m not sick?
Even if you feel healthy, NLR can help detect subtle shifts in your immune system. Your doctor will interpret results alongside other factors like symptoms and lab values.
Can I prepare for this test?
No special preparation is needed, but avoid heavy meals or strenuous activity before the blood draw to ensure 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