Stroke from carotid disease usually results from a partial, and not a complete, blockage of the arteries. This partial blockage results in high velocity turbulence in the blood. The turbulence in turn leads to debris forming from the blockage; as blood continues to course up to the brain, some of this debris may break loose and travel into the brain. If this debris (called an embolus) lodges in the small arteries of the brain, it will block that artery causing a lack of blood flow. That part of the brain will suffer damage as a result.