# Haemostasis and Bleeding Disorders for NEET PG Pathology: ITP, Haemophilia, von Willebrand Disease, Vitamin K Deficiency, DIC, TTP

Source: https://tracknation.in/story/haemostasis-and-bleeding-disorders-for-neet-pg-pathology-itp-haemophilia-von-willebrand-disease-vitamin-k-deficiency-dic-ttp (TrackNation — free UPSC notes with PYQs)

> NEET PG Pathology: how platelets and clotting factors stop bleeding, superficial vs deep bleeding, ITP, haemophilia, von Willebrand disease, Glanzmann and Bernard-Soulier, vitamin K deficiency, DIC, TTP, HUS and antiphospholipid syndrome, with a diagram, hooks, vignette MCQs and cards.

## Start Here

🎯 **Exam priority: Very high.** *Expect: a boy with a swollen knee and prolonged PTT, a child with petechiae after a viral
illness, heavy periods with a family history, a newborn bleeding on day 3, a septic or obstetric patient oozing from lines, and a young woman
with thrombosis and recurrent miscarriage.*

CBME mapping: **PA 20.1–20.2** (and 5.4).

## How Bleeding Stops

- **Adhesion**: von Willebrand factor anchors platelets to exposed collagen via platelet **GP Ib/IX**.

- **Aggregation**: fibrinogen bridges **GP IIb/IIIa** on neighbouring platelets.

- **Coagulation**: tissue factor with factor VIIa activates factor X (extrinsic pathway). **Fibrinolysis**: plasmin
dissolves fibrin.

- **Pattern**: skin and mucosal bleeding (petechiae, purpura) = platelet or vessel defect; deep bleeding (joints, muscles) =
clotting-factor defect.

## The Disorders

*Bleeding disorders: bleeding pattern and test results. Drawn by TrackNation.*

- **ITP**: antiplatelet autoantibody, platelets destroyed mainly in the spleen; isolated low platelets with an otherwise normal
CBC and smear; most children recover on their own.

- **Haemophilia**: X-linked recessive; A = factor VIII (about 80%), B = factor IX; joint and muscle bleeds; PTT prolonged,
PT and platelets normal; factor assays tell them apart.

- **von Willebrand disease**: type 1 (commonest) is autosomal dominant; bruising, mucosal bleeding, heavy periods, bleeding
after tooth extraction; test VWF antigen and ristocetin cofactor activity; desmopressin or factor VIII concentrate.

- **Platelet function**: Glanzmann (AR) lacks GP IIb/IIIa — platelets cannot aggregate; Bernard-Soulier is an adhesion defect.

- **Vitamin K deficiency**: factors II, VII, IX, X not made; PT/INR prolonged, PTT and platelets normal; haemorrhagic disease of
the newborn (days 1–7), commoner in breastfed babies; broad-spectrum antibiotics contribute. Severe liver disease also impairs factor synthesis.

- **DIC**: low platelets, prolonged PT and PTT, high D-dimer, falling fibrinogen; schistocytes; causes include sepsis and
obstetric complications (placental abruption). Replace platelets, plasma and fibrinogen (cryoprecipitate).

- **TTP**: Coombs-negative haemolysis with low ADAMTS13; treated by plasma exchange. **HUS**: usually children after
Shiga-toxin *E. coli* O157:H7; kidney injury prominent.

- **Antiphospholipid syndrome**: thrombosis or recurrent pregnancy loss; lupus anticoagulant *prolongs* the PTT in the lab
despite causing clots.

## Traps the Examiner Sets

- Prolonged PTT with normal PT: haemophilia (or lupus anticoagulant). Prolonged PT alone: vitamin K deficiency.

- Everything abnormal (platelets, PT, PTT, fibrinogen, D-dimer): DIC.

- Mucosal bleeding with a normal platelet count: think von Willebrand disease.

- APS: a lab test says "bleeding risk" but the patient clots.

## Memory Hooks & Shortcuts

*Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.*

- 🧠 **Ib for Initial (adhesion), IIb/IIIa for Integration (aggregation)** — platelet receptors

- 🧠 **Haemophilia: boys, joints, PTT** — X-linked, haemarthroses, prolonged PTT

- 🧠 **Vitamin K: 2, 7, 9, 10 (1972)** — vitamin K-dependent factors

- 🧠 **DIC: Down platelets, Increased D-dimer, Consumed fibrinogen** — DIC labs

- 🧠 **TTP: ADAMTS13 Tiny → Thrombi** — low ADAMTS13

- 🧠 **APS: Prolonged test, Paradoxical clots, Pregnancy loss** — lupus anticoagulant

## Rapid-Revision Cards

- VWF + GP Ib/IX.

- Fibrinogen + GP IIb/IIIa.

- Tissue factor + VIIa → X.

- Plasmin.

- Platelet or vessel.

- Coagulation factors.

- Antiplatelet antibody; isolated thrombocytopenia; children recover.

- X-linked; A = VIII (80%), B = IX; PTT ↑, PT normal.

- Type 1 AD; mucosal bleeding; ristocetin cofactor; desmopressin.

- AR; GP IIb/IIIa; no aggregation.

- Adhesion defect.

- II, VII, IX, X; PT ↑, PTT normal.

- Days 1–7; breastfed infants.

- Platelets ↓, PT/PTT ↑, D-dimer ↑, fibrinogen ↓.

- Low ADAMTS13; Coombs-neg haemolysis; plasma exchange.

- Children; E. coli O157:H7; kidney injury.

- Clots + pregnancy loss; lupus anticoagulant prolongs PTT.

## Sources

*Facts in this article were checked against these documents.*

- MSD Manual Professional: Overview of Hemostasis; Excessive Bleeding; Immune Thrombocytopenia; Hemophilia; von Willebrand Disease; Inherited Platelet Function Disorders; Overview of Coagulation Disorders; DIC; TTP; HUS; Antiphospholipid Syndrome; Vitamin K Deficiency — Merck & Co. (MSD Manuals), reviewed 2025–2026 (link)

- Competency Based Undergraduate Curriculum, Pathology (PA 20) — National Medical Commission, 2024

## Test Yourself: Practice Questions

Twenty-five 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 6-year-old boy has a swollen, painful knee after a minor fall; his maternal uncle had similar bleeds. PTT is prolonged; PT and platelets are normal. The diagnosis is

- (a) vitamin K deficiency

- (b) von Willebrand disease

- (c) ITP

- (d) haemophilia

**Answer: (d)** — X-linked recessive; factor VIII or IX deficiency.

**Q2.** Haemophilia A is due to deficiency of

- (a) factor IX

- (b) factor VIII (about 80% of haemophilia)

- (c) factor VII

- (d) von Willebrand factor

**Answer: (b)** — Haemophilia B is factor IX.

**Q3.** Haemophilia A and B are distinguished by

- (a) platelet count

- (b) PT

- (c) bleeding pattern

- (d) specific factor VIII and IX assays

**Answer: (d)** — Clinical features and screening tests are identical.

**Q4.** Bleeding into joints and muscles suggests

- (a) a vessel wall defect

- (b) a platelet defect

- (c) normal haemostasis

- (d) a clotting-factor defect (coagulopathy)

**Answer: (d)** — Superficial bleeding suggests platelets or vessels.

**Q5.** Petechiae and gum bleeding suggest

- (a) a platelet or vessel problem

- (b) haemophilia

- (c) factor XIII deficiency

- (d) vitamin K deficiency only

**Answer: (a)** — MSD.

**Q6.** Two weeks after a viral illness, a child has petechiae; platelets are 15,000/µL with an otherwise normal blood count and smear. The diagnosis and outlook are

- (a) immune thrombocytopenia; most children recover spontaneously

- (b) aplastic anaemia; poor

- (c) haemophilia; lifelong

- (d) ALL; poor

**Answer: (a)** — Isolated thrombocytopenia.

**Q7.** In ITP, platelets are destroyed mainly in the

- (a) spleen

- (b) kidney

- (c) lungs

- (d) liver

**Answer: (a)** — Antiplatelet autoantibodies.

**Q8.** A woman has lifelong heavy periods, nosebleeds and bleeding after a tooth extraction; her mother is similar. Platelets are normal. The likely diagnosis is

- (a) von Willebrand disease (type 1, autosomal dominant)

- (b) Glanzmann

- (c) ITP

- (d) haemophilia A

**Answer: (a)** — Mucosal bleeding, menorrhagia.

**Q9.** A test of von Willebrand factor function is

- (a) PT

- (b) D-dimer

- (c) osmotic fragility

- (d) ristocetin cofactor activity

**Answer: (d)** — Along with VWF antigen.

**Q10.** Initial platelet adhesion to damaged vessel wall requires von Willebrand factor and the platelet receptor

- (a) thromboxane receptor

- (b) glycoprotein Ib/IX

- (c) glycoprotein IIb/IIIa

- (d) P2Y12

**Answer: (b)** — IIb/IIIa mediates aggregation.

**Q11.** A child with severe nosebleeds has platelets that do not aggregate; the defect is in GP IIb/IIIa. The diagnosis is

- (a) ITP

- (b) Glanzmann thrombasthenia (autosomal recessive)

- (c) haemophilia

- (d) Bernard-Soulier syndrome

**Answer: (b)** — MSD.

**Q12.** Bernard-Soulier syndrome is a disorder of platelet

- (a) adhesion

- (b) production

- (c) aggregation only

- (d) survival

**Answer: (a)** — Like von Willebrand disease (impaired ristocetin response).

**Q13.** A breastfed baby not given vitamin K at birth starts bleeding on day 3. PT/INR is prolonged; PTT and platelets are normal. The diagnosis is

- (a) DIC

- (b) haemophilia

- (c) haemorrhagic disease of the newborn (vitamin K deficiency)

- (d) ITP

**Answer: (c)** — Usually days 1–7; commoner in breastfed infants.

**Q14.** Vitamin K is needed to make clotting factors

- (a) XI and XII

- (b) V and VIII

- (c) II, VII, IX and X

- (d) I and XIII

**Answer: (c)** — Made in the liver.

**Q15.** In vitamin K deficiency, the coagulation tests show

- (a) prolonged PTT only

- (b) high D-dimer

- (c) low platelets

- (d) prolonged PT/INR with normal PTT, platelets and fibrinogen

**Answer: (d)** — MSD.

**Q16.** A woman with placental abruption oozes from IV sites; platelets are low, PT and PTT are prolonged, D-dimer is high and fibrinogen is falling. The diagnosis is

- (a) DIC

- (b) vitamin K deficiency

- (c) haemophilia

- (d) ITP

**Answer: (a)** — Obstetric complications are classic triggers.

**Q17.** In DIC with a very low fibrinogen, fibrinogen is replaced with

- (a) packed red cells

- (b) vitamin K alone

- (c) cryoprecipitate

- (d) albumin

**Answer: (c)** — Plus platelets and fresh frozen plasma.

**Q18.** A woman has confusion, low platelets and Coombs-negative haemolytic anaemia with schistocytes; ADAMTS13 is very low. The diagnosis and treatment are

- (a) DIC — heparin

- (b) TTP — plasma exchange

- (c) HUS — antibiotics

- (d) ITP — steroids alone

**Answer: (b)** — MSD.

**Q19.** A 4-year-old develops kidney injury, low platelets and haemolysis a week after bloody diarrhoea. The usual cause is

- (a) Giardia

- (b) Salmonella typhi

- (c) rotavirus

- (d) Shiga toxin-producing E. coli O157:H7 (HUS)

**Answer: (d)** — HUS usually follows such an infection in children.

**Q20.** A young woman with recurrent miscarriages and a DVT has a prolonged PTT. The likely diagnosis is

- (a) vitamin K deficiency

- (b) von Willebrand disease

- (c) haemophilia carrier

- (d) antiphospholipid syndrome (lupus anticoagulant)

**Answer: (d)** — Lupus anticoagulant prolongs phospholipid-dependent tests yet causes thrombosis.

**Q21.** Fibrinogen links activated platelets together by binding to

- (a) collagen

- (b) tissue factor

- (c) glycoprotein Ib/IX

- (d) glycoprotein IIb/IIIa

**Answer: (d)** — MSD.

**Q22.** The extrinsic pathway starts when factor VIIa combines with

- (a) factor XII

- (b) kallikrein

- (c) factor VIII

- (d) tissue factor, activating factor X

**Answer: (d)** — MSD.

**Q23.** Fibrin is broken down by

- (a) thrombin

- (b) factor XIII

- (c) plasmin

- (d) antithrombin

**Answer: (c)** — Activated by tissue plasminogen activator.

**Q24.** A man with cirrhosis bleeds easily with prolonged clotting times. The main reason is

- (a) ITP

- (b) excess vitamin K

- (c) haemophilia

- (d) impaired clotting-factor synthesis by the liver

**Answer: (d)** — MSD.

**Q25.** A child with severe mucosal bleeding has unusually large platelets that do not aggregate with ristocetin but aggregate normally with ADP, collagen and epinephrine. The defect is in

- (a) ADAMTS13

- (b) glycoprotein Ib/IX (Bernard-Soulier syndrome)

- (c) glycoprotein IIb/IIIa (Glanzmann)

- (d) factor VIII

**Answer: (b)** — Glanzmann (IIb/IIIa): aggregation absent with ADP, collagen and epinephrine; ristocetin response normal or impaired (MSD).

### Active Recall

From memory: describe platelet adhesion and aggregation and the start of coagulation, the bleeding pattern that points to platelets vs factors, and the defect and test pattern in ITP, haemophilia, von Willebrand disease, Glanzmann, vitamin K deficiency, DIC, TTP, HUS and APS.