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

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

This test measures the ratio of neutrophils to lymphocytes in your blood, which can help assess immune response and inflammation levels.

Quick summary

["NLR helps doctors evaluate immune health and inflammation during illness or recovery."]

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

Key facts at a glance

LOINC
105771-0
Short code
N men DNA Ct Bld Pos Qn NAA+probe
Synonyms
N men DNA Ct Bld Pos Qn 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. Neutrophils are part of your body’s first line of defense against infections, while lymphocytes help with long-term immunity. The NLR compares their counts to identify shifts that may signal infection, inflammation, or other health conditions.

Why Is NLR Tested?

Doctors may order this test to monitor conditions like infections, autoimmune diseases, or cancer. It can also help track how your body responds to treatments or recover from illness.

How Is the Test Performed?

A small blood sample is drawn from your arm. The test measures the ratio of neutrophils to lymphocytes using an automated immunoassay method, which detects and quantifies these cells.

What Does NLR Mean for My Health?

A higher NLR may suggest an active infection, inflammation, or stress response, while a lower NLR could indicate a stronger immune response or recovery. Your doctor will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance of NLR includes assessing immune function, monitoring chronic diseases (e.g., cancer, heart disease), and guiding treatment decisions in acute or chronic conditions where inflammation or infection is suspected.

Short name

NLR (Whole Blood)

Frequently asked questions

Why might my doctor order this test?
Your doctor may recommend this test if you have symptoms like fever, fatigue, or signs of infection, or if you’re undergoing treatment for conditions like cancer, heart disease, or autoimmune disorders.
What are typical reference ranges for NLR?
Reference ranges vary by lab and individual health status. A ratio above 2.5 is often considered elevated in some contexts, but your doctor will provide specific guidance based on your results.
Can I affect my NLR results before the test?
Yes, factors like recent infections, stress, illness, or certain medications can influence NLR. Avoiding intense physical activity or infections for a few days before testing may help provide 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