NLR (neutrophils/lymphocytes)
Immune system healthAlso known as: neutrophil-to-lymphocyte ratio, neutrophil lymphocyte ratio, Neutrophile-Lymphozyten-Ratio
NLR reflects the balance between neutrophils which drive early inflammation and lymphocytes which regulate immune control.
Reference range
Source: Ahead Health benchmark
Reference ranges may vary between labs and assays. Always interpret results with your healthcare provider.
Why this matters
Higher values indicate inflammatory or physiological stress. NLR is associated with cardiovascular risk, severe infections, cancer prognosis, and metabolic dysfunction. It helps detect immune imbalance early.
How this connects to other biomarkers
- NLR (Neutrophils/Lymphocytes) > 3 reflects systemic inflammatory stress and is independently associated with worse outcomes in cardiovascular disease, cancer, infection, and critical illness.
- NLR rises with acute bacterial infection (high Neutrophils (abs.), low Lymphocytes (abs.)), corticosteroid use, and chronic stress.
- The Systemic Immune-Inflammation Index (SII) and Systemic Inflammation Response Index (SIRI) integrate platelet/monocyte counts for richer prognostic information.
How often should I test NLR (neutrophils/lymphocytes)?
Most adults benefit from yearly NLR reassessment as part of a CBC with differential.
At baseline / for screening: Once every 12 months from age 30 as part of a CBC with differential. More frequently if you have a chronic inflammatory condition.
When monitoring an intervention or change: These ratios are tracked alongside the CBC rather than on their own cadence. Retest with your next CBC after a sustained anti-inflammatory lifestyle change (better sleep, weight loss, Mediterranean-style diet). Single values are sensitive to acute illness, recent exercise, and stress, so test under consistent conditions.
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