Phase 1 · Understand the Body — Why the disease behaves the way it does.
The One-Line Truth
The whole disease in one chain
Everything on this page exists to explain this line.
A blood clot briefly plugs a brain artery, then breaks apart before brain cells die—but the next clot might not dissolve in time.
A traffic jam that dissolves
Imagine a highway (carotid artery) carrying delivery trucks (red blood cells carrying oxygen) into a city (brain). A accident (blood clot) suddenly blocks one lane, and trucks back up—the neighborhoods downstream (brain cells fed by that artery) run out of supplies and their workers stop moving instantly. But before the neighborhoods suffer permanent damage, a tow truck (tPA enzyme) clears the wreck or it breaks apart on its own, and traffic flows again. The workers wake back up and resume work perfectly—but the accident-prone intersection (the clot source: atrial fibrillation (an irregular, quivering heartbeat), carotid plaque, or small-vessel disease) is still dangerous. The next accident might happen before backup routes (collateral arteries) can reroute traffic, and this time neighborhoods burn down (stroke, permanent brain cell death).
AHA/ASA 2021 Guideline for Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack · CDC Stroke Facts · Cochrane Stroke Group reviews · NEJM Clinical Practice – Transient Ischemic Attack · reviewed 2026-07-07