General pathology · Hemodynamic disorders
Infarction: red vs white, and what decides the damage !
- Lesion
An infarct is an area of tissue killed by lack of blood. It is white in solid organs with one artery and red in loose tissue or with a dual supply.
Updated 2026-11-01
What it is
An infarct is an area of ischemic necrosis, almost always caused by occlusion of an artery (thrombus or embolus) and less often of a vein. It is white (anemic) when an end artery is blocked in a solid organ, such as the heart, kidney or spleen, and red (hemorrhagic) when there is a dual supply, loose tissue, venous occlusion or reperfusion. The final damage depends on the anatomy of the supply, the speed of the occlusion, the tissue’s sensitivity to hypoxia and the oxygen in the blood.
Key facts
- The liver (hepatic artery and portal vein) and the hand (radial and ulnar arteries) seldom infarct because of their dual supply.
- Anemia, carbon monoxide poisoning or heart failure worsen any infarct by lowering blood oxygen.
- A septic infarct, from an infected embolus, turns into an abscess.
- In sickle cell disease repeated splenic infarcts shrink the spleen into a fibrous remnant (autosplenectomy).
Step by step
- An artery is blocked and the downstream tissue is left without oxygen.
- The most sensitive cells die first: neurons in minutes, myocytes in under an hour, fibroblasts in hours.
- The dead zone takes shape over hours; in red infarcts it fills with blood.
- Acute inflammation reaches the edge within one or two days.
- Macrophages clear the dead tissue and granulation tissue appears.
- A fibrous scar forms; in the brain a cyst ringed by gliosis is left.
Type of infarct by organ
| Organ | Type | Why |
|---|---|---|
| Heart | White (coagulative) | End-artery coronaries; dense myocardium |
| Kidney and spleen | White, wedge-shaped | End arteries in a solid organ |
| Brain | Pale and liquefactive; may turn hemorrhagic on reperfusion | Tissue rich in lipid and enzymes, poor in stroma |
| Lung | Red | Dual supply and spongy tissue |
| Small bowel | Red | Collateral arcades and loose tissue; also from mesenteric venous thrombosis |
| Torsed testis | Red | The vein is blocked first and the artery keeps filling the organ |
Test yourself
Think of the answer, then tap the question to see it.
Why is a pulmonary infarct red?
Because the lung has a dual supply and loose tissue: bronchial blood keeps reaching the necrotic zone.
Which type of necrosis does a cerebral infarct produce?
Liquefactive necrosis; the tissue softens and ends as a cystic cavity.
Why does testicular torsion produce a hemorrhagic infarct?
Because torsion first blocks the thin-walled veins while the artery keeps bringing blood in.
Besides the occlusion, which four factors decide the size of the damage?
The anatomy of the supply, the speed of the occlusion, the tissue’s vulnerability to hypoxia and the blood’s oxygen content.
Related
- Patterns of necrosis: coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous
- The myocardial infarct over time: what the pathologist sees from hours to months
- Watershed areas and the organs most sensitive to ischemia
- Hypoxia, ischemia and reperfusion injury
- Systemic (arterial) thromboembolism
- Granulation tissue and scar formation
Related conditions
- Myocardial Infarction (Heart Attack)
- Ischaemic stroke
- Pulmonary embolism
- Avascular necrosis of the femoral head
- Testicular torsion
- Acute mesenteric ischaemia
- Sickle cell disease
- Central retinal artery occlusion
- Ischaemic colitis
Elsewhere in DurgiPedia
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: Heart attack: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2024); Stroke: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025); Ischemic Stroke (StatPearls (NCBI Bookshelf), 2026).
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Representative model, for educational purposes only.