Every 45 seconds, someone in the United States has a stroke. A stroke can happen when:

• A blood vessel carrying blood to the brain is blocked by a blood clot. This is called an ischemic stroke.

• A blood vessel breaks open, causing blood to leak into the brain. This is a hemorrhagic stroke.

If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen.

Brain cells can die, causing permanent damage.