Iron Status Interpreter

Low transferrin saturation usually reflects reduced circulating iron availability. It is common in iron deficiency.

Low TSAT can also be seen in chronic inflammation, infection, autoimmune disease, kidney disease, and malignancy, where hepcidin-mediated iron sequestration reduces circulating iron availability despite normal or elevated ferritin. Obesity and insulin resistance may be associated with this inflammatory low-iron-availability pattern.

High transferrin saturation reflects excess circulating iron relative to binding capacity. TSAT is sensitive to recent iron intake, fasting status, and time of day, so high values should be interpreted cautiously after recent iron supplementation or a non-fasting blood draw.

High TSAT can also be seen with liver disease, and disorders with ineffective erythropoiesis or hemolysis, such as sideroblastic anemia, thalassemia/myelodysplasia, and some hemolytic anemias.

Low MCH is most commonly seen when red blood cells carry less hemoglobin than expected, especially with iron deficiency. It can also be seen with hemoglobinopathies such as thalassemia and with inflammation from chronic conditions.

High MCH means each red blood cell carries more hemoglobin than expected and often tracks with macrocytic patterns. Common contexts include vitamin B12 or folate insufficiency, long-term alcohol use, thyroid disease, and medication or treatment effects.

Low RDW usually reflects uniformly sized red blood cells. It is infrequent and clinically meaningless.

In context, it can be seen when erythropoiesis is stable and there is no meaningful nutrient deficiency signal in the CBC pattern.

High RDW is commonly seen with iron, folate, or vitamin B12 insufficiency, mixed anemia patterns, inflammation, and recovery phases after blood loss or treatment.

Higher RDW has also been associated with worse cardiometabolic and mortality outcomes in cohort studies, so it should be interpreted with hemoglobin, MCV, ferritin, B12, and inflammatory markers.

Low MCV indicates microcytic red blood cells, most commonly from iron deficiency.

Other causes: thalassemia, sideroblastic anemia, anemia of chronic disease, vitamin B6 or copper deficiency, lead poisoning.

High MCV indicates macrocytic red blood cells, most commonly from vitamin B12 deficiency (incl. pernicious anemia) or folate deficiency.

Other causes: alcohol use, liver disease, hypothyroidism, hemochromatosis, megaloblastic or myelodysplastic anemia, elevated reticulocytes.

Low hemoglobin usually indicates anemia and therefore reduced oxygen-carrying capacity.

Common causes include iron deficiency, vitamin B12 or folate deficiency, chronic kidney disease (low EPO), chronic inflammatory disease, bone marrow suppression, blood loss, and hemolysis.

In endurance athletes, low hemoglobin can also reflect dilutional effects from plasma volume expansion rather than true red-cell deficit.

High hemoglobin suggests erythrocytosis or hemoconcentration.

Common causes include dehydration, smoking, chronic hypoxia (sleep apnea, lung disease, high altitude exposure), testosterone or anabolic androgen use, and primary marrow disorders such as polycythemia vera.

Persistent elevations warrant context with hematocrit, RBC count, oxygen status, and medication/supplement review.