[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Blood vessels](https://durgical.com/en/general-pathology/areas/vessels/) › Consequences of atherosclerosis

# Consequences of atherosclerosis

- Process

Plaques hurt in two ways: slowly, by narrowing the artery, and suddenly, when they crack and a clot forms on them.

Updated Nov 12, 2026

## Key points

- Critical stenosis (around 70 % narrowing) causes ischemia on demand: stable angina, intermittent claudication.
- Rupture of a thin cap is the main trigger of myocardial infarction; erosion over an intact plaque is the next cause.
- Triggers of rupture: inflammation degrading collagen (metalloproteinases), sympathetic surges, morning blood pressure peak.
- Atheroembolism: cholesterol crystal emboli to kidney, gut, skin (livedo, blue toe), often after catheter procedures.
- Aortic plaques weaken the media: abdominal aortic aneurysm.

## What it is

Atherosclerosis causes disease through slow narrowing (critical stenosis, usually when about 70 % of the lumen is lost, so blood flow cannot rise with demand) and through sudden events. Acute plaque change, meaning rupture or fissuring of the cap, superficial erosion, or bleeding inside the plaque, exposes thrombogenic material and leads to a thrombus that may block the artery. Plaque material and clot can embolise downstream, and in the aorta the thinned media allows aneurysms.

## Structure

- Ruptured plaque: broken cap with plaque contents protruding into the lumen and an overlying platelet-fibrin thrombus.
- Cholesterol embolus: needle-shaped empty clefts (cholesterol dissolved during processing) in small arteries, with giant cells.

## Step by step

- A plaque grows slowly; the artery first remodels outward and the lumen is preserved.
- Once the lumen narrows enough, flow cannot rise with demand: ischemia with effort.
- Inflammation thins the cap; stress fissures or ruptures it, or the endothelium over it erodes.
- Tissue factor and collagen in the plaque meet blood; platelets aggregate and a thrombus forms.
- A partial thrombus causes unstable ischemia; a complete one causes infarction.
- The thrombus organises or plaque fragments embolise; repeated cycles enlarge the plaque.

## Where atherosclerosis strikes and what it causes

| Territory | Lesion | Disease |
| --- | --- | --- |
| [Coronary arteries](https://durgical.com/en/conditions/myocardial-infarction/) | Stenosis, rupture with thrombus | Angina, myocardial infarction, sudden death |
| [Carotid and cerebral arteries](https://durgical.com/en/conditions/ischaemic-stroke/) | Stenosis, ulcerated plaque with emboli | Transient ischemic attack, ischemic stroke |
| [Mesenteric arteries](https://durgical.com/en/conditions/chronic-mesenteric-ischemia/) | Ostial stenosis, thrombosis | Intestinal angina, mesenteric infarction |
| [Arteries of the legs](https://durgical.com/en/conditions/peripheral-artery-disease/) | Stenosis, thrombosis | Claudication, critical limb ischemia, gangrene |
| [Abdominal aorta](https://durgical.com/en/conditions/abdominal-aortic-aneurysm/) | Medial thinning under plaques | Abdominal aortic aneurysm |
| [Renal arteries and small vessels](https://durgical.com/en/conditions/atheroembolic-renal-disease/) | Ostial stenosis, cholesterol emboli | Renovascular hypertension, atheroembolic kidney disease |

## Clinical notes

- Most myocardial infarctions start on plaques that were only moderately stenotic, which is why stress tests miss many people at risk.

## Memory aid

Plaques either choke slowly or crack suddenly; the crack is what kills.

## Test yourself

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

## At roughly what degree of narrowing does a plaque cause ischemia on exertion?

Around 70 % of the lumen (critical stenosis); at that point flow cannot increase with demand.

## What is the commonest event that turns a plaque into an acute coronary syndrome?

Rupture or fissuring of the fibrous cap with thrombosis on the exposed core; erosion is the second mechanism.

## What does a cholesterol embolus look like under the microscope?

Empty needle-shaped clefts in small arteries, left where the cholesterol crystals dissolved, often with a giant-cell reaction.

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## Elsewhere in DurgiPedia

- [Acute limb ischemia and chronic arterial insufficiency](https://durgical.com/en/clinical-exam/acute-limb-ischemia-and-chronic-arterial-insufficiency/)
- [Coronary circulation and myocardial ischemia](https://durgical.com/en/physiology/coronary-circulation-and-myocardial-ischemia/)

## Connections

## Related 8

- [Atherosclerotic plaque: stable vs vulnerable](https://durgical.com/en/general-pathology/atherosclerotic-plaque-stable-vs-vulnerable/)
- [Ischaemic heart disease](https://durgical.com/en/general-pathology/ischaemic-heart-disease/)
- [Abdominal aortic aneurysm: the lesion, its variants and rupture](https://durgical.com/en/general-pathology/abdominal-aortic-aneurysm-the-lesion-its-variants-and-rupture/)
- [Infarction: red vs white, and what decides the damage](https://durgical.com/en/general-pathology/infarction-red-vs-white-and-what-decides-the-damage/)
- [Arterial vs venous thrombi; mural thrombi and lines of Zahn](https://durgical.com/en/general-pathology/arterial-vs-venous-thrombi-mural-thrombi-and-lines-of-zahn/)
- [Systemic (arterial) thromboembolism](https://durgical.com/en/general-pathology/systemic-thromboembolism/)
- [Fat, air and amniotic fluid embolism](https://durgical.com/en/general-pathology/fat-air-and-amniotic-fluid-embolism/)
- [Ischaemic bowel disease](https://durgical.com/en/general-pathology/ischaemic-bowel-disease/)

## Related conditions 10

- [Myocardial Infarction (Heart Attack)](https://durgical.com/en/conditions/myocardial-infarction/)
- [Ischaemic stroke](https://durgical.com/en/conditions/ischaemic-stroke/)
- [Peripheral artery disease](https://durgical.com/en/conditions/peripheral-artery-disease/)
- [Chronic mesenteric ischemia](https://durgical.com/en/conditions/chronic-mesenteric-ischemia/)
- [Acute limb ischaemia](https://durgical.com/en/conditions/acute-limb-ischaemia/)
- [Atheroembolic renal disease (cholesterol crystal embolism)](https://durgical.com/en/conditions/atheroembolic-renal-disease/)
- [Stable angina](https://durgical.com/en/conditions/stable-angina/)
- [Carotid artery stenosis](https://durgical.com/en/conditions/carotid-artery-stenosis/)
- [Renovascular hypertension (renal artery stenosis)](https://durgical.com/en/conditions/renovascular-hypertension/)
- [Transient ischaemic attack](https://durgical.com/en/conditions/transient-ischaemic-attack/)

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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: [Atherosclerosis | Arteriosclerosis | MedlinePlus](https://medlineplus.gov/atherosclerosis.html) (MedlinePlus, US National Library of Medicine, 2025); [Coronary Artery Disease | CAD | MedlinePlus](https://medlineplus.gov/coronaryarterydisease.html) (MedlinePlus, US National Library of Medicine, 2025).

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