Blood Health
Absolute Band Neutrophils
What This Marker Tells Us
Measures immature neutrophils recently released from bone marrow; their presence indicates your body is rapidly producing neutrophils in response to infection or inflammation.
Why It Matters
Band neutrophils (also called "stabs" or "bands") are immature neutrophils one stage before full maturity. Normally, bone marrow releases mostly mature neutrophils with only occasional bands. When fighting infection or inflammation, your bone marrow accelerates neutrophil production and releases immature bands into circulation, a phenomenon called a "left shift." Elevated bands indicate active bacterial infection, severe inflammation, or bone marrow stress. The higher the band count, the more urgent the situation. Bands above 10% of total neutrophils suggest significant infection requiring immediate attention. Very high bands may indicate severe infection (sepsis), tissue necrosis, or rarely leukemia. Band counts help distinguish bacterial infections (elevated bands) from viral infections (normal or low bands) and assess infection severity.
How to Interpret Your Trends
Normal band neutrophils are 0-500 cells/μL (0-5% of WBC). Bands of 500-1,000 cells/μL (5-10%) indicate mild left shift from bacterial infection or inflammation. Bands above 1,000 cells/μL (above 10%) suggest significant bacterial infection or severe inflammation requiring prompt treatment. Very high bands (above 2,000-3,000 cells/μL or above 20%) may indicate severe infection, sepsis, or bone marrow disorders. Rising bands over time indicate worsening infection or inadequate treatment. Falling bands during antibiotic treatment confirm improving infection.
What Influences This Marker
Bands increase with bacterial infections (pneumonia, UTI, cellulitis, appendicitis), severe inflammation, tissue necrosis, burns, trauma, surgery, labor and delivery, certain medications (G-CSF), and acute leukemia. They decrease as infections resolve with treatment. Viral infections typically don't cause elevated bands. Chronic inflammation rarely causes significant band elevation; bands specifically indicate acute processes.
How Your Team Uses It
Your coach supports recovery from infection through adequate rest, hydration, protein intake to support immune cell production, and temporarily reducing training intensity to allow immune system focus. Elevated bands indicate medical attention is needed, not a time for pushing physical limits.
Related Signals We Also Review
Absolute neutrophils, total WBC, more immature cells (metamyelocytes, myelocytes), hs-CRP, procalcitonin if available, and clinical symptoms for infection severity assessment.