Neutrophil-to-lymphocyte ratio (NLR) measured via automated blood cell differential probe
This test compares the number of neutrophils (a type of white blood cell) to lymphocytes (another type of white blood cell) in your blood. It’s often used to help assess inflammation or infection.
["NLR helps doctors check for inflammation or infection in your blood."]
Key facts at a glance
- LOINC
- 71788-4
- Short code
- N men DNA Spec NAA+probe
- Synonyms
- N men DNA Spec NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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
Why Is This Test Done?
Your doctor may order an NLR test to evaluate symptoms like fever, fatigue, or unexplained weight loss. It can also help monitor conditions such as infections, autoimmune diseases, or certain cancers. NLR is sometimes used alongside other blood tests to guide treatment decisions.
What Does a High or Low NLR Mean?
A higher NLR often suggests inflammation, infection, or stress on your immune system. A lower NLR might indicate conditions like chronic inflammation, certain cancers, or immune suppression. However, results depend on your overall health and other factors.
How Is This Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The sample is analyzed using a machine that counts and identifies different types of white blood cells, including neutrophils and lymphocytes.
What Are Common Uses?
NLR is commonly used in routine blood tests, especially in settings like emergency departments or during cancer treatment. It can also help track how well certain conditions are responding to treatment over time.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: NLR is a simple, non-invasive marker that reflects the balance between two key immune cells. Elevated NLR is frequently associated with acute infections, inflammatory diseases, or stress responses, while persistently low NLR may suggest chronic inflammation, immunosuppression, or certain malignancies. It’s often used as a quick, cost-effective tool alongside other tests to guide clinical decisions.
Short name
NLR (Blood Count)
Frequently asked questions
What does an NLR test measure exactly?
Can an NLR test replace other blood tests?
How often should I get an NLR test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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