General pathology · Hemodynamic disorders
Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does !
- Lesion
Blood outside the vessels takes different forms by size and cause; its effect depends on how much, how fast and where it is lost.
Updated 2026-11-01
What it is
Hemorrhage is the escape of blood from the vessels. In skin and mucosa it is named by size: pinpoint petechiae, slightly larger purpura, extensive ecchymosis, and hematoma when it forms a collection. The pattern points to the defect: platelets and capillaries give petechiae; clotting factors give deep bleeding into joints and muscles. Severity depends on volume, speed and site: a small bleed in the brain can be fatal.
Step by step
- A vessel tears or hemostasis fails and blood leaks into the tissue.
- The escaped red cells look red; macrophages engulf them.
- Heme oxygenase turns heme into biliverdin (green), then bilirubin (yellow).
- The iron stays as brown hemosiderin, which is why a bruise turns brown before it fades.
- If the loss is fast and large, circulating volume falls and hypovolemic shock follows.
Forms of hemorrhage
| Form | What it looks like | Typical cause |
|---|---|---|
| Petechiae | Tiny red dots that do not blanch on pressure | Thrombocytopenia, platelet dysfunction, vasculitis, meningococcemia |
| Purpura | Somewhat larger spots; palpable when there is vasculitis | Platelets, vasculitis, vessel fragility |
| Ecchymosis | Extensive bruise that changes colour | Trauma, anticoagulation, factor defects |
| Hematoma | A collection of blood that forms a lump | Trauma, hemophilia; epidural or subdural in the skull |
| Bleeding into a cavity | Hemothorax, hemopericardium, hemoperitoneum, hemarthrosis | Trauma, ruptured aneurysm, hemophilia |
Clinical notes
- Mucosal bleeding and petechiae suggest a platelet or von Willebrand factor problem.
- Bleeding into joints and muscles, and delayed bleeding after surgery, suggest a factor deficiency (hemophilia A or B).
- Rapid hemopericardium causes cardiac tamponade even when the volume is small.
- In the closed skull, an epidural or subdural hematoma raises intracranial pressure and can herniate the brain.
In the lab
- Platelet count and bleeding time point to platelet defects; PT and aPTT to factor defects.
- Hemosiderin is shown with Perls’ stain.
Test yourself
Think of the answer, then tap the question to see it.
What kind of defect usually produces petechiae?
A platelet problem (number or function) or a capillary problem, as in immune thrombocytopenia or vasculitis.
Why does a bruise turn green and then brown?
Hemoglobin is broken down to biliverdin and bilirubin, and the iron stays behind as brown hemosiderin.
What does spontaneous hemarthrosis in a boy suggest?
A clotting factor deficiency, typically hemophilia A or B.
Why does slow, chronic blood loss not cause shock?
Because the body replaces the volume; what appears instead is iron-deficiency anemia from the iron lost.
Related
- Shock: types, stages and the organs it damages
- Disseminated intravascular coagulation: how consumption causes both clots and bleeding
- Pigments in tissue: lipofuscin, hemosiderin, melanin, bilirubin, carbon
- Hyperemia and congestion (the nutmeg liver, heart-failure cells)
Related conditions
- Immune thrombocytopenia (ITP)
- Haemophilia A and B
- Von Willebrand disease
- Thrombotic thrombocytopenic purpura
- IgA vasculitis (Henoch–Schönlein purpura)
- Meningococcal disease (meningococcemia)
- Intracerebral haemorrhage
- Epidural haematoma
- Subdural haematoma
- Upper gastrointestinal bleeding
- Postpartum haemorrhage
- Hypovolaemic shock
- Iron deficiency anaemia
- Vitamin K deficiency bleeding of the newborn
Elsewhere in DurgiPedia
- Primary hemostasis and platelets
- Coagulation tests: PT/INR, aPTT and platelets
- Heme oxygenase
- Biliverdin reductase
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 into the skin: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025); Bleeding: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025); Hypovolemic shock: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025).
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Representative model, for educational purposes only.