Stroke is a brain injury. It occurs when the blood supply to the brain is interrupted. Without oxygen and nutrients from blood, brain tissue dies in less than 10 minutes. The tissue death causes a sudden loss in function.
A stroke occurs when there is a loss of blood flow. It may happen because of a blockage in blood flow, called ischemic stroke, or because of bleeding in the brain, called hemorrhagic stroke.
A sudden decrease in the flow of blood may be caused by:
- A clot that breaks off from another part of the body (such as the heart or neck) and lodges in blood vessel of neck or brain—there are certain conditions which predispose people to form blood clots, such as:
- A blood clot that forms in neck or brain
- Atherosclerosis —a build-up of fatty substances along the inner lining of the artery that gradually decrease the area the blood can flow through
- Inflammatory conditions in the blood vessels (vasculitis)
Hemorrhagic stroke occur when blood vessels break and bleed into or around the brain. This can happen after an injury.
Hemorrhagic vs. Ischemic Stroke
Copyright © Nucleus Medical Media, Inc.
Last reviewedSeptember 2012by Rimas Lukas, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.