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Neutrophil-to-Lymphocyte Ratio (NLR) in Plasma

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

This test measures the ratio of your white blood cells’ neutrophils to lymphocytes in plasma, a simple way to assess immune response and inflammation.

Quick summary

["NLR helps doctors check how your body’s immune system is responding to infection or illness."]

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

Key facts at a glance

LOINC
99092-9
Short code
N men DNA CSF Ql NAA+probe
Synonyms
N men DNA CSF Ql NAA+probe
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Is Neutrophil-to-Lymphocyte Ratio (NLR)?

Neutrophils and lymphocytes are two types of white blood cells that fight infections. NLR compares their counts to identify shifts that may signal inflammation, infection, or other health concerns. This ratio is often calculated from a blood sample but can also be derived from plasma, depending on the lab method.

Why Is This Test Done?

Doctors may order NLR testing to evaluate symptoms like fever, fatigue, or unexplained weight loss, especially when other tests suggest inflammation or immune dysfunction. It’s also used in monitoring conditions like cancer, autoimmune diseases, or chronic infections.

How Is the Test Performed?

A blood sample is drawn, and the plasma is analyzed to count neutrophils and lymphocytes. The ratio is calculated automatically by the lab equipment, often as part of a routine complete blood count (CBC) or separately if needed.

What Do Results Mean?

Higher NLR may indicate active infection, inflammation, or stress, while lower ratios could suggest immune suppression or certain chronic conditions. However, results alone aren’t diagnostic—they’re used alongside other tests and patient history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

NLR (Plasma)

Frequently asked questions

How long does it take to get my NLR results?
Results are typically available within 1–2 business days, depending on lab processing times. Your doctor will discuss them with you during your follow-up visit.
Can I influence my NLR results?
Yes, factors like recent infections, stress, dehydration, or certain medications (e.g., steroids) can temporarily affect NLR. Avoiding extreme physical activity or infections before testing may help get more accurate results.
Is NLR the same as a complete blood count (CBC)?
No, NLR is a calculated ratio derived from neutrophil and lymphocyte counts in a CBC or plasma sample. While both tests assess white blood cells, NLR focuses specifically on their relative proportions.
  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