[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Red cells and bleeding disorders](https://durgical.com/en/general-pathology/areas/red-cells/) › Bleeding disorders: overview

# Bleeding disorders: overview

- Topic

Bleeding comes from weak vessels, too few or faulty platelets, or missing clotting factors. Where and how a patient bleeds shows which.

Updated Nov 12, 2026

## Key points

- Platelet or vessel pattern: petechiae, purpura, mucosal bleeding, immediate bleeding after cuts.
- Factor pattern: haemarthroses, deep muscle haematomas, delayed bleeding after trauma; petechiae absent.
- PT tests extrinsic and common pathways (factor VII, X, V, II, fibrinogen); PTT tests intrinsic and common (XII, XI, IX, VIII, X, V, II).
- Vessel-wall defects: platelet count, PT and PTT all normal.
- DIC: low platelets, long PT and PTT, low fibrinogen, high D-dimer.

## What it is

Haemostasis depends on the vessel wall, platelets and the coagulation cascade, and a hemorrhagic diathesis can arise from a defect in any of them. Vessel and platelet defects cause mucocutaneous bleeding: petechiae, purpura, nosebleeds, gum bleeding and heavy menses. Clotting factor deficiencies cause deep bleeding into joints and muscles and delayed oozing after surgery or dental extraction. A short set of tests (platelet count, PT, PTT, fibrinogen, D-dimer, platelet function tests) usually sorts the problem.

## Step by step

- Vessel injury exposes collagen and von Willebrand factor; reflex vasoconstriction slows flow.
- Platelets adhere through GPIb–vWF, activate, release ADP and thromboxane and aggregate through GPIIb/IIIa–fibrinogen.
- Tissue factor triggers the cascade; thrombin makes fibrin that stabilizes the platelet plug.
- A defect in the wall or platelets fails the first, immediate plug: mucosal and skin bleeding.
- A factor defect lets a plug form but not hold: delayed and deep bleeding.

## Sorting bleeding disorders with basic tests

| Defect | Bleeding pattern | Platelet count | PT | PTT |
| --- | --- | --- | --- | --- |
| [Vessel wall (scurvy, vasculitis, HHT)](https://durgical.com/en/conditions/scurvy/) | Petechiae, purpura, mucosal | Normal | Normal | Normal |
| [Thrombocytopenia (ITP, marrow failure)](https://durgical.com/en/conditions/immune-thrombocytopenia/) | Petechiae, mucosal, intracranial risk | Low | Normal | Normal |
| [Platelet function (Glanzmann, Bernard–Soulier, aspirin, uraemia)](https://durgical.com/en/conditions/inherited-platelet-function-disorders/) | Mucocutaneous | Normal (low and large in Bernard–Soulier) | Normal | Normal |
| [von Willebrand disease](https://durgical.com/en/conditions/von-willebrand-disease/) | Mucosal, heavy menses | Normal | Normal | Normal or long |
| [Haemophilia A or B](https://durgical.com/en/conditions/haemophilia-a-and-b/) | Joints, muscles, delayed | Normal | Normal | Long |
| [DIC, liver disease, vitamin K deficiency](https://durgical.com/en/conditions/disseminated-intravascular-coagulation/) | Mixed, oozing from sites | Low in DIC, normal otherwise | Long | Long or normal |

## Clinical notes

- A personal and family history (surgery, tooth extraction, menses, childbirth) is the best screening tool.
- Mixing studies tell factor deficiency (corrects) from an inhibitor (does not).

## Memory aid

Skin and mucosa: platelets or vessels. Joints and muscles: factors. Both at once: think DIC or liver.

## Test yourself

Think of the answer, then tap the question to see it.

## What bleeding pattern suggests a clotting factor deficiency?

Deep bleeding into joints and muscles and delayed bleeding after trauma or surgery, without petechiae.

## Which basic tests are normal in vessel-wall bleeding disorders?

Platelet count, PT and PTT are all normal.

## What is the lab pattern of DIC?

Low platelets, prolonged PT and PTT, low fibrinogen and high D-dimer.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/bleeding-disorders-overview/)

[More Pathology questions →](https://durgical.com/en/practice/?f=pathology)

## Elsewhere in DurgiPedia

- [Coagulation tests: PT/INR, aPTT and platelets](https://durgical.com/en/physiology/coagulation-tests-pt-inr-aptt-and-platelets/)
- [Primary hemostasis and platelets](https://durgical.com/en/physiology/primary-hemostasis-and-platelets/)
- [The coagulation cascade](https://durgical.com/en/physiology/the-coagulation-cascade/)
- [Bleeding syndromes: platelet vs coagulation pattern](https://durgical.com/en/clinical-exam/bleeding-syndromes-platelet-vs-coagulation-pattern/)

## Connections

## Related 5

- [Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does](https://durgical.com/en/general-pathology/hemorrhage-petechiae-purpura-ecchymosis-hematoma-and-what-blood-loss-does/)
- [Disseminated intravascular coagulation: how consumption causes both clots and bleeding](https://durgical.com/en/general-pathology/disseminated-intravascular-coagulation-how-consumption-causes-both-clots-and-ble/)
- [Thrombocytopenia: mechanisms](https://durgical.com/en/general-pathology/thrombocytopenia-mechanisms/)
- [Haemophilia A and B](https://durgical.com/en/general-pathology/haemophilia-a-and-b/)
- [Acquired coagulation factor disorders](https://durgical.com/en/general-pathology/acquired-coagulation-factor-disorders/)

## Related conditions 6

- [Immune thrombocytopenia (ITP)](https://durgical.com/en/conditions/immune-thrombocytopenia/)
- [Haemophilia A and B](https://durgical.com/en/conditions/haemophilia-a-and-b/)
- [Von Willebrand disease](https://durgical.com/en/conditions/von-willebrand-disease/)
- [Disseminated intravascular coagulation](https://durgical.com/en/conditions/disseminated-intravascular-coagulation/)
- [Inherited platelet function disorders (Glanzmann thrombasthenia, Bernard–Soulier syndrome)](https://durgical.com/en/conditions/inherited-platelet-function-disorders/)
- [Scurvy (vitamin C deficiency)](https://durgical.com/en/conditions/scurvy/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Bleeding Disorders | MedlinePlus](https://medlineplus.gov/bleedingdisorders.html) (MedlinePlus, US National Library of Medicine, 2026); [Platelet Disorders | MedlinePlus](https://medlineplus.gov/plateletdisorders.html) (MedlinePlus, US National Library of Medicine, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/general-pathology/bleeding-disorders-overview/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/bleeding-disorders-overview/