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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 neutrophils to lymphocytes in your blood, which can help assess immune response and inflammation levels.

Quick summary

["NLR helps doctors understand your body’s immune balance and possible infection or inflammation."]

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

Key facts at a glance

LOINC
81612-4
Short code
NM Hrt BP+EF+FP W RNC IV
Synonyms
NM Hrt BP+EF+FP W RNC IV
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nm
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 the NLR Test Used For?

Doctors may use the NLR test to evaluate conditions like infections, autoimmune diseases, or cancer. It can also help monitor treatment progress or response to illness.

How Is the NLR Test Performed?

A small blood sample is drawn from a vein, typically in your arm. The blood is analyzed to count the types of white blood cells, including neutrophils and lymphocytes.

What Does an NLR Result Mean?

Higher NLR may suggest inflammation, infection, or certain cancers, while lower NLR could indicate a stronger immune response or less inflammation. Results are interpreted by your healthcare provider.

Common Conditions Monitored

NLR is often checked in patients with infections (like pneumonia or sepsis), inflammatory diseases (such as rheumatoid arthritis), or cancer (like leukemia or lymphoma).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Why might my doctor order an NLR test?
Your doctor may order this test if they suspect an infection, inflammation, or other immune-related condition. It can also help track how your body responds to treatment.
Is the NLR test painful?
The blood draw is mild discomfort, similar to a standard blood test. Most people feel little to no pain afterward. A small bandage may be applied.
How soon will I get my results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will explain them in detail during your follow-up.
  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