Phase 1 · Understand the Body — Why the disease behaves the way it does.
The One-Line Truth
The whole disease in one chain
Everything on this page exists to explain this line.
Chronic inflammation raises hepcidin (a liver hormone that locks iron inside storage cells) so the bone marrow cannot reach that iron to build red blood cells, even though total body iron is normal or high.
The Locked Warehouse During a Lockdown
Imagine a warehouse (your body) that normally restocks shelves (bone marrow) with iron daily. During a normal day, workers (macrophages) unload recycled iron from old pallets (dead red blood cells) onto the loading dock, and dock workers (ferroportin channels) push it into delivery trucks (blood). But when a fire alarm (chronic inflammation) goes off, the warehouse manager (liver) panics and locks all the dock doors (destroys ferroportin), trapping iron inside. The iron is still there—piled high—but no trucks can leave. At the same time, the radio that calls for rush orders (erythropoietin from the kidneys) goes quiet because everyone is focused on the emergency. So the shelves don't get restocked, even though there's plenty of iron locked inside, because the gate is shut and nobody's placing orders.
KDIGO 2012 Clinical Practice Guideline for Anemia in Chronic Kidney Disease · American Society of Hematology (ASH) guidelines on anemia management · FDA Safety Communication on Erythropoiesis-Stimulating Agents · AABB (American Association of Blood Banks) Clinical Practice Guidelines on Red Blood Cell Transfusion 2016 · reviewed 2026-07-07