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Neutrophil-to-Lymphocyte Ratio (NLR) – Calculated from Blood Count

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

This test measures the ratio of neutrophils to lymphocytes in your blood, calculated from a complete blood count (CBC). It helps assess immune response and inflammation levels.

Quick summary

["NLR can indicate inflammation or infection and may guide treatment decisions."]

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

Key facts at a glance

LOINC
30097-0
Short code
N men sg W135 Ag Spec Ql LA
Synonyms
N men sg W135 Ag Spec Ql LA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
la
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

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

Neutrophils are a type of white blood cell that fight infections, while lymphocytes are part of the immune system that help fight chronic infections and diseases. The NLR compares these two cell types to gauge overall immune activity. A higher ratio may suggest inflammation, infection, or other health concerns.

Why Is This Test Done?

Your healthcare provider may order this test to evaluate symptoms like fever, fatigue, or signs of infection. It can also help monitor conditions such as cancer, autoimmune diseases, or inflammatory disorders.

How Is the Test Performed?

A small blood sample is drawn from a vein, typically in your arm. The sample is analyzed to count neutrophils and lymphocytes, and the ratio is calculated automatically.

What Do the Results Mean?

Results are not given as a single numeric range but as a ratio (e.g., 1.5:1). Higher ratios may indicate acute infection, inflammation, or other health issues, while lower ratios may suggest immune suppression or chronic conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

NLR (Blood)

Frequently asked questions

What does a high NLR mean?
A high NLR may signal an active infection, inflammation, or other conditions like cancer or autoimmune diseases. Your doctor will interpret results in the context of your symptoms and medical history.
What does a low NLR mean?
A low NLR could suggest immune suppression, chronic diseases like certain cancers, or conditions affecting white blood cell function. It may also indicate a less acute inflammatory state.
How often should I get this test?
The frequency depends on your health status and treatment plan. Your doctor will determine if repeat testing is needed, especially if you have ongoing symptoms or conditions requiring 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