Anemia – Types and Blood Tests

1. Iron deficiency anemia – The most prevalent form of anemia worldwide, triggered by inadequate dietary intake, impaired intestinal absorption, or chronic occult blood loss. Erythrocytes exhibit characteristic microcytosis (diminished MCV) and hypochromia (diminished MCH) due to defective heme synthesis.

2. Aplastic anemia – A rare, life-threatening bone marrow failure disorder characterized by hematopoietic stem cell destruction and marked pancytopenia, frequently precipitated by viral infections, autoimmune processes, or toxic chemical exposure.

3. Hemolytic anemia – Arises when red blood cell survival drops drastically below the normal 120-day lifespan due to accelerated intra- or extravascular destruction. Hallmark findings include elevated indirect bilirubin, clinical jaundice, increased urinary urobilinogen, and diminished circulating haptoglobin.

4. Post-hemorrhagic anemia – Develops subsequent to acute massive hemorrhage (trauma, surgical complications, gastrointestinal ulcer rupture) or heavy uterine bleeding. It manifests clinically with acute hypotension, compensatory tachycardia, pallor, and orthostatic dizziness.

5. Anemia of pregnancy – Affects up to 40% of expectant mothers as plasma volume expansion (hemodilution) outpaces erythrocytic mass increases. Daily iron requirements surge to approximately 27 mg to sustain fetal development and placental tissue growth.

6. Anemia of chronic disease (ACD) – Associated with systemic inflammation, chronic infections, autoimmune pathologies, and malignancies. Inflammatory cytokines like interleukin-6 drive hepatic hepcidin overproduction, sequestering iron within macrophages and blunting erythropoietin responsiveness.