Ischemic Stroke

Skip Navigation
A clot blocking blood flow to an area of the brain

An ischemic stroke develops when a blood vessel (artery) supplying blood to an area of the brain becomes blocked by a blood clot. The clot may form in the blood vessel (thrombus) or travel from somewhere else in the blood system (embolus).

About 80 out of 100 strokes are ischemic strokes. They are the most common type of stroke in older adults.

Current as of: March 4, 2020

Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine
Martin J. Gabica, MD - Family Medicine
Adam Husney, MD - Family Medicine
Richard D. Zorowitz, MD - Physical Medicine and Rehabilitation




The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.