# Haematology Basics and Microcytic Anaemia for NEET PG Pathology: Iron Deficiency, Anaemia of Chronic Disease, Thalassaemia Trait Source: https://tracknation.in/story/haematology-basics-and-microcytic-anaemia-for-neet-pg-pathology-iron-deficiency-anaemia-of-chronic-disease-thalassaemia-trait (TrackNation — free UPSC notes with PYQs) > NEET PG Pathology: red-cell production, defining and working up anaemia (MCV, reticulocytes, RDW), sample tubes, Indian anaemia cut-offs, iron metabolism and the stages of iron deficiency, and how to tell iron deficiency from anaemia of chronic disease, beta-thalassaemia trait and sideroblastic anaemia, with a diagram, hooks, vignette MCQs and cards. ## Start Here 🎯 **Exam priority: Very high.** *Expect: a woman with fatigue and low ferritin, a microcytic picture with high RBC count (thalassaemia trait), anaemia of chronic disease in rheumatoid arthritis, ring sideroblasts, and the tube colour for a blood count.* CBME mapping: **PA 13.1–13.4, 14.1–14.2**. Indian cut-offs: **Anemia Mukt Bharat**. ## Making Red Cells - Red cells are made in the marrow under **erythropoietin**, produced by peritubular interstitial fibroblasts of the kidney in response to low oxygen delivery. - They live about **120 days**; reticulocytes make up 0.5–2.5% of adult red cells. - **Extramedullary haematopoiesis** (mainly in the spleen) is seen in myelofibrosis, which also gives nucleated and teardrop red cells. ## Anaemia: Definition and Work-up - Anaemia is a fall in red-cell number, lowering haematocrit and haemoglobin. Start with a **CBC, reticulocyte count and peripheral smear**. - **Microcytic** if MCV < 80 fL; **macrocytic** if MCV > 100 fL (many reticulocytes can raise the MCV). The reticulocyte count shows how well the marrow is compensating. - **Tubes** (WHO): EDTA, purple top — haematology and cross-match; citrate, light blue — coagulation tests. Both work by binding calcium. Indian cut-offs for anaemia (Hb, g/dL; Anemia Mukt Bharat): | **Group** | **Mild** | **Moderate** | **Severe** | | Children 6–59 months | 10–10.9 | 7–9.9 | < 7 | | Pregnant women | 10–10.9 | 7–9.9 | < 7 | | Non-pregnant women (≥ 15 y) | 11–11.9 | 8–10.9 | < 8 | | Men (≥ 15 y) | 11–12.9 | 8–10.9 | < 8 | ## Iron Deficiency - The **commonest cause of anaemia**, usually from **blood loss**. Iron is absorbed in the duodenum and upper jejunum, best as haem iron; low stores suppress **hepcidin**, raising absorption. - **Stages**: stores fall first (ferritin < 30 ng/mL with normal Hb), then iron-starved red-cell production, then microcytosis and hypochromia. - **Labs**: low ferritin and serum iron, high TIBC. Smear: anisocytosis, poikilocytosis; cigar-shaped cells in severe cases; no polychromasia or basophilic stippling. - **Clues**: pica; spoon-shaped nails (koilonychia). In men and postmenopausal women without obvious loss, examine the GI tract. - **Response to iron**: reticulocytes rise after about 1 week; Hb starts rising after 1–2 weeks. ## Telling Microcytic Anaemias Apart *Iron deficiency, anaemia of chronic disease, beta-thalassaemia trait and sideroblastic anaemia compared. Drawn by TrackNation.* - **Anaemia of chronic disease**: raised hepcidin traps iron in macrophages; serum iron and transferrin low, ferritin normal or high; normocytic early, then microcytic. - **Beta-thalassaemia trait**: mild microcytic anaemia with a *raised* red-cell count; Hb A2 > 3.5–4% is diagnostic (normal ≤ 2.5%); no treatment needed. - **Sideroblastic anaemia**: iron cannot enter protoporphyrin IX; high serum iron, ferritin and saturation; ring sideroblasts. Acquired forms are usually part of myelodysplastic syndrome. ## Traps the Examiner Sets - Low ferritin = iron deficiency; normal/high ferritin with low iron = chronic disease. - Microcytosis with a high RBC count suggests thalassaemia trait, not iron deficiency. - Iron deficiency in an older man: look for a GI cancer. - Purple (EDTA) for counts, light blue (citrate) for clotting. ## Memory Hooks & Shortcuts *Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.* - 🧠 **Ferritin Falls First** — the earliest sign of iron deficiency - 🧠 **FIT test: Ferritin low, Iron low, TIBC high** — iron deficiency labs - 🧠 **Chronic disease Clings to iron (hepcidin)** — ferritin normal or high - 🧠 **Thal trait: Tiny cells, Too many (high RBC), A2 Above 3.5** — beta-thalassaemia minor - 🧠 **Ring around the nucleus = Sideroblastic** — ring sideroblasts - 🧠 **Purple for counting, Blue for clotting** — EDTA vs citrate tubes ## Rapid-Revision Cards - Kidney peritubular interstitial fibroblasts. - ~120 days; reticulocytes 0.5–2.5%. - Spleen; myelofibrosis (teardrop cells). - CBC, reticulocyte count, smear. - Microcytic < 80 fL; macrocytic > 100 fL. - Purple; CBC, cross-match. - Light blue; coagulation. - Mild 10–10.9, moderate 7–9.9, severe < 7. - Mild 11–12.9, moderate 8–10.9, severe < 8. - Iron deficiency (blood loss). - Duodenum, upper jejunum; haem best; hepcidin falls. - Ferritin < 30 with normal Hb. - Low ferritin, low iron, high TIBC. - Aniso-poikilocytosis; cigar cells; no stippling. - Pica, koilonychia. - Look for GI cancer. - Retics at ~1 wk; Hb rises 1–2 wk. - High hepcidin; low iron and transferrin; ferritin normal/high. - Microcytic, high RBC count; Hb A2 > 3.5–4%. - High iron/ferritin; ring sideroblasts; MDS. ## Sources *Facts in this article were checked against these documents.* - MSD Manual Professional: Red Blood Cell Production; Etiology and Evaluation of Anemia; Iron Deficiency Anemia; Anemia of Chronic Disease; Sideroblastic Anemias; Thalassemias; Primary Myelofibrosis — Merck & Co. (MSD Manuals), reviewed 2025–2026 (link) - WHO guidelines on drawing blood: best practices in phlebotomy — World Health Organization, 2010 (link) - Anemia Mukt Bharat: Operational Guidelines — Ministry of Health and Family Welfare, 2018 - Competency Based Undergraduate Curriculum, Pathology (PA 13–14) — National Medical Commission, 2024 ## Test Yourself: Practice Questions Twenty-four questions in NEET PG style, most of them clinical vignettes. ## Practice Questions (NEET PG pattern) *Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.* **Q1.** A 32-year-old woman with heavy periods has Hb 9 g/dL, MCV 70 fL, low serum ferritin and high TIBC. The diagnosis is - (a) beta-thalassaemia trait - (b) sideroblastic anaemia - (c) anaemia of chronic disease - (d) iron deficiency anaemia **Answer: (d)** — Low ferritin and serum iron with high TIBC. **Q2.** The commonest cause of anaemia, usually due to blood loss, is - (a) iron deficiency - (b) thalassaemia - (c) vitamin B12 deficiency - (d) aplastic anaemia **Answer: (a)** — MSD. **Q3.** The earliest laboratory change as iron stores fall, while haemoglobin is still normal, is - (a) microcytosis - (b) a fall in serum ferritin (< 30 ng/mL) - (c) a fall in Hb - (d) hypochromia **Answer: (b)** — Stores deplete first; microcytosis and hypochromia come in stage 3. **Q4.** Iron is absorbed mainly in the - (a) terminal ileum - (b) stomach - (c) colon - (d) duodenum and upper jejunum **Answer: (d)** — Haem iron (meat) is absorbed best. **Q5.** A woman with a long-standing autoimmune disease has mild anaemia, low serum iron, low transferrin and a high ferritin. The mechanism is - (a) B12 deficiency - (b) blood loss - (c) ineffective globin synthesis - (d) raised hepcidin sequestering iron (anaemia of chronic disease) **Answer: (d)** — Hepcidin blocks absorption and recycling; ferritin normal or high. **Q6.** A 25-year-old has Hb 11.5 g/dL, MCV 64 fL and a raised red-cell count; he feels well. The likely diagnosis is - (a) severe iron deficiency - (b) aplastic anaemia - (c) anaemia of chronic disease - (d) beta-thalassaemia trait **Answer: (d)** — Trait: microcytic anaemia with elevated RBC count, usually asymptomatic. **Q7.** In that man, the finding diagnostic of beta-thalassaemia minor is - (a) Hb F of 90% - (b) Hb A2 above 3.5–4% - (c) ring sideroblasts - (d) low ferritin **Answer: (b)** — Normal Hb A2 ≤ 2.5%. **Q8.** Beta-thalassaemia trait usually needs - (a) no treatment - (b) iron therapy - (c) splenectomy - (d) regular transfusion **Answer: (a)** — MSD: no intervention is needed. **Q9.** A marrow iron stain shows erythroblasts with a ring of iron-laden mitochondria around the nucleus; serum iron and ferritin are high. This is - (a) anaemia of chronic disease - (b) thalassaemia trait - (c) sideroblastic anaemia - (d) iron deficiency **Answer: (c)** — Iron cannot be incorporated into protoporphyrin IX. **Q10.** Most acquired sideroblastic anaemias are part of - (a) hypothyroidism - (b) thalassaemia - (c) iron deficiency - (d) myelodysplastic syndrome **Answer: (d)** — MSD. **Q11.** A 65-year-old man with no obvious bleeding has iron deficiency anaemia. The next step is - (a) evaluate the GI tract for occult cancer - (b) oral iron only and no tests - (c) bone marrow biopsy - (d) Hb electrophoresis **Answer: (a)** — Anaemia may be the only sign of occult GI cancer. **Q12.** A child with iron deficiency craves and eats non-food substances. This is called - (a) glossitis - (b) koilonychia - (c) pica - (d) dysphagia **Answer: (c)** — MSD: suspect iron deficiency, particularly if pica is present. **Q13.** Spoon-shaped, concave nails in an anaemic woman suggest - (a) haemolysis - (b) B12 deficiency - (c) thalassaemia - (d) iron deficiency (koilonychia) **Answer: (d)** — MSD image caption. **Q14.** In severe iron deficiency, the smear characteristically shows - (a) anisocytosis, poikilocytosis and cigar-shaped cells, without polychromasia - (b) target cells with basophilic stippling - (c) macro-ovalocytes - (d) spherocytes **Answer: (a)** — Polychromasia and basophilic stippling are conspicuously absent. **Q15.** After starting oral iron, the first sign of response is - (a) Hb normal at 3 days - (b) MCV normal at 1 week - (c) ferritin normal at 1 day - (d) a reticulocyte rise after about 1 week **Answer: (d)** — Hb begins to rise after 1–2 weeks. **Q16.** A red-cell population is called microcytic when MCV is below - (a) 60 fL - (b) 100 fL - (c) 80 fL - (d) 90 fL **Answer: (c)** — Macrocytic is > 100 fL. **Q17.** A patient bleeding acutely has a high reticulocyte count and a slightly raised MCV. The MCV is raised because - (a) reticulocytes are larger than mature red cells - (b) of lab error - (c) of iron deficiency - (d) of B12 deficiency **Answer: (a)** — Large numbers of reticulocytes can elevate the MCV. **Q18.** A blood sample for a complete blood count should be collected in the tube with - (a) EDTA (purple top) - (b) clot activator (red top) - (c) fluoride (grey top) - (d) citrate (light blue top) **Answer: (a)** — WHO: EDTA for haematology and cross-match; citrate for coagulation. **Q19.** For a prothrombin time, blood is collected in - (a) EDTA (purple top) - (b) a plain tube - (c) heparin - (d) sodium citrate (light blue top) **Answer: (d)** — WHO phlebotomy guideline. **Q20.** Erythropoietin is produced mainly by - (a) the spleen - (b) hepatocytes - (c) peritubular interstitial fibroblasts of the kidney - (d) bone marrow stromal cells **Answer: (c)** — In response to decreased oxygen delivery. **Q21.** A man with splenomegaly and marrow fibrosis has teardrop and nucleated red cells on his smear. The spleen is enlarged partly from - (a) iron overload - (b) thalassaemia trait - (c) B12 deficiency - (d) extramedullary haematopoiesis (myelofibrosis) **Answer: (d)** — MSD: primary myelofibrosis. **Q22.** Under Anemia Mukt Bharat, a pregnant woman with Hb 6.5 g/dL has - (a) mild anaemia - (b) severe anaemia (< 7 g/dL) - (c) moderate anaemia - (d) no anaemia **Answer: (b)** — Pregnant women: mild 10–10.9, moderate 7–9.9, severe < 7. **Q23.** Under Anemia Mukt Bharat, a man with Hb 12 g/dL has - (a) mild anaemia (11–12.9) - (b) no anaemia - (c) severe anaemia - (d) moderate anaemia **Answer: (a)** — Men ≥ 15 y: mild 11–12.9, moderate 8–10.9, severe < 8. **Q24.** Normal adult red cells survive about - (a) 30 days - (b) 1 year - (c) 7 days - (d) 120 days **Answer: (d)** — Then cleared mainly by the spleen. ### Active Recall From memory: explain red-cell production and lifespan, the first tests for anaemia and the MCV cut-offs, the sample tubes, the stages and lab picture of iron deficiency, and how anaemia of chronic disease, beta-thalassaemia trait and sideroblastic anaemia differ from it.