| Red‑blood‑cell (RBC) count, hemoglobin, hematocrit |
Oxygen‑carrying capacity; anemia vs. polycythemia |
Looks for hidden nutrient deficits (iron, B12, folate, copper), chronic low‑grade inflammation, gut malabsorption, and hormonal influences (thyroid, adrenal) that can blunt erythropoiesis. |
| Mean corpuscular volume (MCV) |
Size of RBCs – macro‑ vs. micro‑cytic patterns |
Signals specific micronutrient gaps (e.g., high MCV → B12/folate deficiency; low MCV → iron, zinc, or chronic infection). Functional practitioners often pair MCV with ferritin, transferrin saturation, and methylation markers. |
| White‑blood‑cell (WBC) count |
Overall immune cell load; infection, leukopenia, leukocytosis |
Serves as a “stress barometer.” Elevated WBC can reflect systemic inflammation, dysbiosis, or environmental toxin exposure. Low WBC may hint at bone‑marrow stress, chronic viral load, or nutritional insufficiency (selenium, vitamin D). |
| Differential (neutrophils, lymphocytes, monocytes, eosinophils, basophils) |
Identifies which immune lineages dominate |
Functional medicine interprets shifts as clues to underlying drivers: • Neutrophil predominance – acute bacterial stress, gut permeability (“leaky gut”) allowing endotoxin translocation. • Lymphocyte elevation – viral reactivation (EBV, CMV), chronic fatigue, or autoimmune activation. • Monocytosis – ongoing tissue repair, low‑grade inflammation, or heavy metal burden. • Eosinophilia – allergic or parasitic load, gut dysbiosis, food sensitivities. |
| Platelet count |
Clotting ability; thrombocytosis/ thrombocytopenia |
Platelets are increasingly recognized as participants in inflammation and endothelial health. Functional clinicians assess: • High platelets – chronic inflammatory states, iron deficiency, or estrogen excess. • Low platelets – oxidative stress, nutrient depletion (vitamin K, omega‑3 fatty acids), or marrow suppression from toxins. |
