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