Neutrophil-to-Lymphocyte Ratio (NLR)
A ratio worked out from two white blood cell counts. A higher value is a general sign of stress or inflammation, not a diagnosis.
AI-verified against cited sources. Awaiting expert reviewAlso called NLR, N/L
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What it is
The neutrophil-to-lymphocyte ratio (NLR) compares two kinds of white blood cell. Neutrophils are first responders that rise quickly with infection, injury and stress. Lymphocytes are the cells behind longer-term immune defense, and they often fall when the body is under stress. You get the NLR by dividing the absolute neutrophil count by the absolute lymphocyte count from a complete blood count (CBC) with differential. Using the two percentages gives the same number.
Why it matters
The NLR packs two results into one number that tends to rise when the body is under stress or inflammation. Researchers study it as a low-cost, general marker in infection, heart disease and cancer. In a US government health survey (NHANES), adults over 30 with a higher NLR had higher death rates on average over the following years. It does not diagnose any condition, it has no official cutoffs, and many ordinary things can move it, so it is most useful as one clue alongside your other results.
If it’s low
A low NLR means neutrophils are low compared with lymphocytes. This is usually just normal variation, and a low ratio on its own is rarely a concern. One author has described values below about 0.7 as unusual, but this is not an official cutoff.
Common causes
- Normal variation, since some healthy people naturally have lower neutrophil counts
- A high lymphocyte count, which can follow some viral infections
- A low neutrophil count (neutropenia) from any cause
What can help
- Look at the neutrophil and lymphocyte counts themselves, since those are what your lab flags
- Ask your clinician whether a repeat count is needed
If it’s high
A higher NLR means neutrophils are high compared with lymphocytes. It is a general sign that the body's stress or inflammation response is active. It is not specific, so it cannot tell you the cause. Mildly high values are common in people who are otherwise well.
Common causes
- Physical or emotional stress, including hard exercise
- A recent infection, especially a bacterial one
- Steroid medicines
- Smoking or excess body weight
- Long-term conditions such as diabetes, heart disease or other chronic illness
- Inflammation linked to some cancers
- Anemia
What can help
- Ask your clinician to look at the neutrophil and lymphocyte counts behind the ratio, and at CRP if inflammation is a question
- Consider rechecking once any recent illness, injury or major stress has passed
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
For adults: 0.78–3.53 ratio. Source: BMC Research Notes, Medicine (Baltimore), Caspian Journal of Internal Medicine, Scientific Reports.
- Adults (this one applies)0.78–3.53 ratio
Sources: BMC Research Notes, Medicine (Baltimore), Caspian Journal of Internal Medicine, Scientific Reports
See NLR by age and sex, with the U.S. survey numbers where they exist.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore NLR by age and sex: every percentile as a table, with a download.
What can affect your result
- Age and ethnicity, which shift the usual white cell counts
- Acute stress, exercise and steroid medicines
- Infection, injury, surgery and inflammatory flares
- Smoking, body weight and long-term conditions
- Anemia
- The quality of the differential count your lab reports
- Acute stress, hard exercise and steroid medicines raise neutrophils and lower lymphocytes, which pushes the ratio up.
- A recent infection or flare of an inflammatory condition can raise it.
- Smoking, obesity and some long-term conditions are linked to a higher ratio.
- The ratio depends on your lab's differential count, so its accuracy is only as good as those two counts.
Can shift within hours to days of an infection, injury or major stress.
When to talk to a clinician
The ratio itself is not an urgent value. If your lab flags a very low neutrophil count, or if you have a fever and feel very unwell, contact a clinician promptly, whatever the ratio shows.
Questions you could ask
- Is the ratio useful for anything I'm being followed for, or are the individual counts enough?
- Could stress, a recent illness or a medicine I take explain this?
- Should we repeat my blood count or add a CRP test?
- Are my neutrophil and lymphocyte counts themselves in the usual range?
- Should we recheck this in a few weeks?
Questions people ask
What is a normal NLR?
There is no official cutoff. In a study of healthy adults aged 21 to 66, most had values from about 0.8 to 3.5, with an average near 1.65. Some authors describe 1 to 2 as typical and above 3 as raised. Your own trend over time can say more than one number.
Does a high NLR mean something is wrong?
Not by itself. Stress, hard exercise, a recent cold, smoking and steroid medicines can all raise it. A clinician looks at it together with your symptoms and other results, and may ask whether a repeat test would help.
Do I need a special test for NLR?
No. It comes from a standard complete blood count with differential. Many labs do not print it, but you can work it out by dividing the absolute neutrophil count by the absolute lymphocyte count.
Show the science and sources
For clinicians and researchers
NLR is the absolute neutrophil count divided by the absolute lymphocyte count, and because the two percentages share the same total, the percentage ratio is identical. Zahorec described it in critically ill patients (2001) as a marker of the stress response, in which cortisol and catecholamines raise neutrophils and lower lymphocytes. In a 2021 review he reported a typical adult range of 1 to 2, a grey zone of 2.3 to 3.0, and values above 3.0 or below 0.7 as pathological, with values above 11 seen in critical illness and a fall below 7 with improvement; these are expert proposals and not consensus thresholds. Forget et al. (2017) measured 413 healthy workers aged 21 to 66 and found a mean of 1.65 and a 95% range (mean plus or minus 1.96 SD) of 0.78 to 3.53, with values in the same range from several analyzers in a second small control group of 29. Healthy-adult averages were similar in South Korea (1.65, n = 12,160; Lee 2018) and Iran (1.70, n = 2,212; Moosazadeh 2019). NHANES 1999 to 2014 adults over 30, not restricted to healthy people, had a mean of 2.3, and higher NLR quartiles were associated with higher all-cause and some cause-specific mortality (hazard ratio 1.14 per quartile). NLR is influenced by age, ethnicity, medication, chronic disease, obesity, anemia and stress. It is sensitive but not specific, and thresholds differ between studies, so it is best used as a trend within one person rather than as a diagnostic cutoff.
Sources
- What is the normal value of the neutrophil-to-lymphocyte ratio?, BMC Research Notes (2017)
- Neutrophil-to-lymphocyte ratio, past, present and future perspectives, Bratislava Medical Journal (Bratislavske lekarske listy) (2021)
- Neutrophil-to-lymphocyte ratio and mortality in the United States general population, Scientific Reports (2021)
- Reference values of neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, platelet-lymphocyte ratio, and mean platelet volume in healthy adults in South Korea, Medicine (Baltimore) (2018)
- Normal values of neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio and platelet-to-lymphocyte ratio among Iranian population: Results of Tabari cohort, Caspian Journal of Internal Medicine (2019)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.