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Neutrophil-to-lymphocyte ratio (NLR) calculated from whole blood cell counts

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
31917-8
Short code
N men sg C Ag Spec Ql
Synonyms
N men sg C Ag Spec Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 white blood cells that fight bacterial infections, while lymphocytes help with long-term immunity. An NLR compares these two cell types. Elevated neutrophils may indicate infection or inflammation, while higher lymphocytes could suggest immune activation or recovery. This ratio is often calculated from a routine blood test.

Why Is NLR Used?

Doctors may use NLR to monitor conditions like infections, autoimmune diseases, or cancer. It can also guide treatment decisions, especially in acute illnesses or post-surgery recovery.

How Is NLR Measured?

NLR is derived from a standard blood count test, where your healthcare provider calculates the ratio of neutrophils to lymphocytes based on their counts in your blood sample.

Clinical Uses of NLR

NLR is commonly used in settings like cancer care, sepsis monitoring, or inflammatory conditions. It may help track how your body responds to treatment or identify worsening symptoms early.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

NLR is a simple, non-invasive test that provides insight into immune balance. While not a standalone diagnosis, it supports broader clinical decisions alongside other tests and symptoms.

Short name

NLR (Blood Count Ratio)

Frequently asked questions

What does an elevated NLR mean?
An elevated NLR may suggest an active infection, inflammation, or immune response. However, it can also occur in stress, trauma, or certain chronic conditions. Your doctor will consider your full medical picture.
What does a low NLR mean?
A low NLR might indicate a suppressed immune response, but it can also reflect normal immune balance or certain immune disorders. Always discuss results with your healthcare provider.
Can NLR be affected by medications?
Yes, certain medications (e.g., steroids, chemotherapy) or conditions (e.g., malnutrition) can influence NLR. Your doctor will review your medical history and other test results before interpreting 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