A stroke happens when the blood flow to the brain is interrupted, usually in one of two ways:
1. A blood clot blocks blood flow to the brain.
This is called an ischemic stroke.
The blood clot may get into the brain by:
- forming in a brain blood vessel (thrombotic stroke)
- forming elsewhere in the body (such as the heart), and moving through the bloodstream to the brain (embolic stroke)
2. Blood vessels burst in the brain.
This is called a hemorrhagic stroke. Blood leaking into the brain and the interruption in blood flow both damage the brain.