Carotid artery disease occurs when fatty deposits, called Arterial Plaque, clog the blood vessels that deliver blood to the brain and head (carotid arteries). The clog increases the risk of stroke. Stroke is a medical emergency that occurs when the brain loses all or much of its blood supply.
During a stroke, the brain doesn't get oxygen and brain cells begin to die within minutes. Stroke is a leading cause of death and disability in the U.S.
Carotid artery disease often develops slowly. The first sign of the condition might be a stroke or transient ischemic attack (TIA). A TIA is a temporary shortage of blood flow to the brain.
https://www.mayoclinic.org/diseases-conditions/carotid-artery-disease/symptoms-causes/syc-20360519