The First Sign of Iron Deficiency! – Medical Must Knows Internal Medicine Test #7

Explanation 📌 Iron Deficiency Anemia (IDA) is the most common cause of anemia worldwide, often due to: 🔴 Chronic Blood Loss – GI bleeding (peptic ulcer, colorectal cancer), heavy menstruation 🥗 Poor Dietary Intake – Low iron consumption (vegetarian/vegan diets) 🩸 Malabsorption – Celiac disease, gastrectomy, H. pylori infection Lab Findings 📉 ↓ Serum Iron 📉 ↓ Ferritin (Most sensitive marker!) 📈 ↑ Total Iron-Binding Capacity (TIBC) (Compensatory increase) 📊 ↑ Red Cell Distribution Width (RDW) (Early IDA) 🔬 Microcytic Hypochromic RBCs on peripheral smear Clinical Presentation 😴 Fatigue, Weakness, Pallor 🥄 Koilonychia (Spoon-Shaped Nails) 👅 Glossitis (Smooth, Inflamed Tongue) 🦷 Angular Cheilitis (Cracks at Mouth Corners) 🧲 Pica (Craving for Non-Food Substances like Ice, Dirt, Chalk) Management 💊 Oral Iron Supplementation – Ferrous sulfate (Best Absorbed with Vitamin C) 🔍 Identify & Treat the Underlying Cause – GI endoscopy if suspecting occult bleeding Differential Diagnosis of Microcytic Anemia IDA → ↓ Ferritin, ↑ TIBC Anemia of Chronic Disease (ACD) → ↑ Ferritin, ↓ TIBC Thalassemia → Normal Iron Studies, Target Cells on Smear Lead Poisoning → Basophilic Stippling References: Harrison’s Principles of Internal Medicine, 21st Edition "Iron Deficiency Anemia: Diagnosis and Treatment" – NEJM, 2022 World Health Organization Guidelines Tags: Internal Medicine, Iron Deficiency Anemia, Microcytic Anemia, Chronic Blood Loss, GI Bleeding, Menorrhagia, Ferritin, Total Iron-Binding Capacity, Pica, Spoon Nails, Hematology, Anemia of Chronic Disease, Vitamin Deficiencies, Thalassemia, Bone Marrow Suppression, Red Blood Cell Indices, Nutritional Deficiencies, Differential Diagnosis of Anemia, Hematology-Oncology, USMLE, PLAB, MRCP, MCCQE, AMC MCQ, NEET PG, AIIMS PG, FRACP, Medical Board Exams Question: Which of the following is the most sensitive indicator of iron deficiency anemia? Options: A) Hemoglobin B) Serum Iron C) Ferritin D) Total Iron-Binding Capacity (TIBC) Answer: C) Ferritin Title: The First Sign of Iron Deficiency! – Medical Must Knows Internal Medicine Test #7 Field: Internal Medicine