Microcytic hypochromic anaemia due to depleted iron stores; commonest anaemia worldwide.
Etiology
- • Blood loss (menstrual, GI)
- • Poor intake / absorption (coeliac, gastrectomy)
- • Increased demand (pregnancy, growth)
History taking
- • Fatigue, dyspnoea, pica, restless legs
- • Menstrual / GI symptoms, diet
Examination
- • Pallor, koilonychia, glossitis, angular cheilitis
Red flags
- • Postmenopausal woman or man with IDA → urgent GI workup
- • Severe symptomatic anaemia
Differential diagnosis
- • See differentials section per chief complaint
Recommended investigations
- • CBC, peripheral smear
- • Ferritin (<30 ng/mL diagnostic), TSAT
- • Coeliac serology, FOBT / colonoscopy / OGD as indicated
Diagnosis
- • Clinical diagnosis supported by targeted investigations
Initial treatment / management
- • Treat underlying cause
- • Symptomatic relief
- • Patient education
Drug therapy
- • Ferrous sulphate 200 mg OD–TDS (or alternate-day dosing for tolerability)
- • IV iron (ferric carboxymaltose) if intolerance / malabsorption / Hb <8 with symptoms
Follow-up advice
- • Hb rise ~10 g/L in 2–4 weeks
- • Continue iron 3 months after Hb normalises to replete stores
Patient counselling
- • Take iron with vitamin C, avoid tea/coffee 1 h either side
- • Constipation, black stool expected
Referral criteria
- • Refer if diagnostic uncertainty, complications, or failure of first-line therapy
Clinical pearls
- • Ferritin can be falsely normal in inflammation — use TSAT < 20% to confirm
References
- • Harrison's Principles of Internal Medicine, 21e
- • NICE / WHO guidelines (current edition)
Educational outpatient guide — verify against local guidelines before clinical use.
