A blood clot travels to the brain when it breaks loose from its original location in the body, enters the bloodstream, and flows through the arteries leading to the brain. Eventually, it lodges in a smaller blood vessel in the brain, blocking blood flow and causing a stroke.
Here's a more detailed explanation:
Formation and Detachment
Blood clots typically form in the heart, large arteries (especially in the neck and chest), or veins. Factors contributing to clot formation include:
- Atrial fibrillation: An irregular heartbeat that can cause blood to pool in the heart.
- Atherosclerosis: Plaque buildup in arteries, which can rupture and trigger clot formation.
- Deep vein thrombosis (DVT): Clots in the deep veins, often in the legs.
- Heart valve problems: Damaged or artificial heart valves can promote clot formation.
A piece of the clot can then break off – this detached piece is called an embolus.
Travel Through the Bloodstream
The embolus enters the bloodstream and is carried through the circulatory system. Because it is now circulating, it can travel throughout the body.
Lodging in the Brain's Blood Vessels
The embolus travels through the arteries leading to the brain, such as the carotid arteries. As it moves further into the brain's circulatory system, it encounters progressively smaller blood vessels. Eventually, the embolus reaches a vessel that is too narrow for it to pass through. This blockage interrupts blood flow to the brain tissue supplied by that vessel.
Ischemic Stroke
When blood flow is blocked, brain cells are deprived of oxygen and nutrients, leading to an ischemic stroke. Brain cells begin to die within minutes of the blockage. The area of the brain affected, and the severity of the stroke, depend on the size and location of the blocked blood vessel.
