Neutrophil-to-lymphocyte ratio (serum/plasma)
This test measures the ratio of neutrophils to lymphocytes in your blood, which can help assess immune response and inflammation levels.
["Neutrophils and lymphocytes are key white blood cells; their balance can signal health or disease."]
Key facts at a glance
- LOINC
- 96978-2
- Short code
- NIP aneu + 22q11.2 Pnl WBC.DNA+cfDNA
- Synonyms
- NIP aneu + 22q11.2 Pnl WBC.DNA+cfDNA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 136
- Ref high
- 145
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- dosage-of-chromosome-specific-cf-dna
- CPT
- 84295
- SNOMED
- 110741000
- 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 bacterial infections, while lymphocytes help manage immune responses and infections. The NLR compares their numbers in your blood. This ratio can be useful in diagnosing conditions like infections, inflammation, or certain cancers.
Why Is NLR Tested?
Doctors may order NLR testing to evaluate immune function, detect infections, or monitor chronic diseases. It’s often used alongside other blood tests to guide treatment decisions.
How Is NLR Measured?
Your blood sample is drawn and analyzed to count neutrophils and lymphocytes. The NLR is calculated by dividing the neutrophil count by the lymphocyte count. This test is typically performed on serum or plasma.
What Does NLR Mean for You?
Higher NLR may suggest inflammation, infection, or stress on your immune system, while lower NLR could indicate a suppressed immune response. Your doctor will interpret results in the context of your symptoms and medical history.
Reference range
Adult: 136-145 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: NLR is a simple, non-invasive marker often used in clinical settings to assess immune status, guide infection management, or monitor conditions like cancer or autoimmune diseases. It complements other tests but isn’t diagnostic alone.
Short name
NLR (Serum/Plasma)
Frequently asked questions
What causes a high NLR?
What causes a low NLR?
How often is NLR tested?
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