Blood Health
Absolute Blasts
What This Marker Tells Us
Measures the most immature blood cell precursors; their presence in peripheral blood almost always indicates acute leukemia or severe bone marrow failure requiring emergency evaluation.
Why It Matters
Blasts are the earliest identifiable blood cell precursors, normally confined to bone marrow where they mature into functional blood cells. Healthy peripheral blood contains zero blasts. Any circulating blasts indicate either acute leukemia (most common) or severe bone marrow stress/failure. Blast percentage determines leukemia diagnosis: 20% or more blasts in blood or marrow defines acute leukemia (AML or ALL). Even 5% circulating blasts is highly abnormal and demands immediate hematologic evaluation and bone marrow biopsy. Blasts crowd out normal blood cell production, causing anemia, thrombocytopenia, and neutropenia, leading to fatigue, bleeding, and infections. Acute leukemia requires emergency chemotherapy to prevent death from infection, bleeding, or organ infiltration.
How to Interpret Your Trends
Normal blasts in peripheral blood: 0 cells/μL (0%). Any detectable blasts are critically abnormal requiring immediate evaluation. Even 1% blasts (one blast per 100 white cells) demands urgent hematology consultation and likely bone marrow biopsy. Blasts of 5-19% indicate probable leukemia or severe myelodysplastic syndrome. Blasts of 20% or higher define acute leukemia (acute myeloid leukemia or acute lymphoblastic leukemia), a medical emergency requiring immediate hospitalization and chemotherapy. Very high blast counts (above 100,000 cells/μL) can cause leukostasis with strokes or respiratory failure.
What Influences This Marker
Blasts appear with acute myeloid leukemia, acute lymphoblastic leukemia, blast crisis of chronic myeloid leukemia, high-grade myelodysplastic syndrome, and rarely with severe bone marrow stress (though this is extremely uncommon). Unlike other immature cells which might appear transiently with infection, blasts nearly always indicate malignancy. Any blasts require emergency hematologic evaluation, peripheral blood smear, bone marrow biopsy, flow cytometry, and genetic testing to diagnose leukemia type and guide treatment.
How Your Team Uses It
Your coach recognizes blasts as a hematologic emergency requiring immediate medical care. Once treatment begins, their role includes supporting treatment adherence, ensuring adequate nutrition during chemotherapy (high protein, calories), infection prevention during profound immune suppression, and emotional support through cancer treatment.
Related Signals We Also Review
Complete blood count (often shows pancytopenia), peripheral blood smear, bone marrow biopsy, flow cytometry, cytogenetics, molecular testing, and emergency hematology/oncology consultation for any circulating blasts.