Iron deficiency anemia (mechanism of disease)

This is a mechanism of disease flowchart for iron deficiency anemia, covering the etiology, pathophysiology, and manifestations of the disease. ADDITIONAL TAGS: Medicine / iatrogenic Infectious / microbial Biochem / molecular bio Hemodynamic physiology Signs / symptoms Labs / tests / imaging results Iron deficiency anemia Core concepts Trauma / blood loss Neoplasm / cancer Diet / nutrition Genetics / hereditary Inflammation Pathophysiology Etiology Manifestations Iron deficiency: body lacks enough iron to meet needs Decreased iron intake Increased blood loss Decreased iron absorption (in duodenum) Increased iron demand GI bleed Hemorrhagic diathesis (hemophilia, vWD) Menorrhagia GI malignancy (colon cancer) NSAIDs Peptic ulcer disease H. pylori infection Atrophic gastritis Hookworm infestation Meckel diverticulum Autoimmune Achlorhydria / hypochlorhydria VIPoma Long-term PPIs IBD, celiac Trauma Inhibit COX-1/2 enzymes → ↓ prostaglandin production → ↓ bicarb and mucus production → gastric acid erodes mucosa Bariatric surgery / duodenal resection Undernutrition Vegan-based diet Pregnancy Lactation Growth spurt EPO therapy ↓ heme synthesis (↓ binding of iron to protoporphyrin) ↓ hemoglobin production Iron def anemia labs: ↓ Hb, ↓ Hct, ↓ ferritin, ↓ iron, ↓ MCV, ↓ MCH, nl/↓ retic Decreased oxygen carrying capacity and delivery of O2 to tissues Fatigue Lethargy Dyspnea Acute decrease in hemodynamic volume ↓ cerebral perfusion (Pre)syncope Pale conjunctiva Koilonychia (spoon- like nail deformity) Pica, dysphagia Angular cheilitis: fissures in corners of mouth Atrophic glossitis: big, beefy, red tongue Pallor ↓ preload ↓ stroke volume ↓ cardiac output ↑ pulmonary venous pressure Pulmonary edema Baroreceptor reflex triggers sympathetic nervous system Tachycardia Long-term cardiac remodeling High-output heart failure