Skip to content

Neutrophil-to-Lymphocyte Ratio (NLR) Assessment

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

This test measures the ratio of your white blood cells, specifically focusing on two types: neutrophils and lymphocytes. It helps your healthcare provider assess your immune response and overall health.

Quick summary

NLR can provide insights into inflammation and immune activity, often used alongside other tests.

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

Key facts at a glance

LOINC
90570-3
Short code
MDSV30RAIV1172TYPEOFASSESSMENTNTNPEST
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cms-assessment
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, especially bacterial ones. Lymphocytes are another type that help your immune system respond to infections and diseases. The NLR compares these two cell counts to give a quick snapshot of your immune balance.

Why Is NLR Tested?

Doctors may order an NLR test to evaluate conditions like infections, inflammation, or certain cancers. It can also help monitor chronic diseases, such as heart disease or autoimmune disorders, where immune activity plays a role.

How Is the Test Performed?

This test uses a simple blood sample drawn from a vein. Your healthcare provider will explain the process and ensure you’re comfortable. The blood is analyzed to count the neutrophils and lymphocytes.

What Does NLR Tell Your Doctor?

A higher NLR might suggest increased inflammation or infection, while a lower ratio could indicate a stronger lymphocyte response. Your doctor will interpret the results in the context of your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

NLR is often used as a quick, non-invasive marker to guide treatment decisions. For example, it may help determine if you need antibiotics for an infection or if your immune response needs support. Some studies also explore its role in predicting outcomes in conditions like cancer or heart disease.

Short name

NLR (Neutrophil-to-Lymphocyte Ratio)

Frequently asked questions

What does an abnormal NLR mean?
An abnormal NLR doesn’t have a single interpretation—it depends on your overall health, symptoms, and other test results. For instance, a very high NLR might signal infection or inflammation, while a very low NLR could suggest conditions like certain cancers or immune deficiencies. Your doctor will discuss the results with you.
How often is NLR tested?
NLR is not a routine test like glucose or cholesterol. It’s typically ordered when your doctor suspects an infection, inflammation, or another condition affecting your immune system. Some chronic diseases may also require periodic monitoring.
Can I prepare for an NLR blood test?
No special preparation is needed for an NLR test. You can eat and drink normally before the test, and you may be asked to fast if your doctor orders additional tests. Rest assured, the process is quick and usually painless.
  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