Skip to content

Stroke Health Center

Select An Article
Font Size

Cause

Causes of ischemic stroke

An ischemic stroke is caused by a blood clot that blocks blood flow to the brain.

  • A blood clot can form in an artery that supplies blood to the brain.
    • Blood clots usually form in arteries damaged by plaque buildup, which is a process called atherosclerosis.
    • Long-term high blood pressure or diabetes may damage smaller blood vessels in the brain, causing a clot to form within the blood vessels and block blood flow.
  • A blood clot can form in another part of the body (often the heart) and travel through the bloodstream to the brain. For example, clots may form:

Low blood pressure may also cause an ischemic stroke, although this is less common. Low blood pressure results in reduced blood flow to the brain. It may be caused by narrowed or diseased arteries, a heart attack, a large loss of blood, or a severe infection.

Recommended Related to Stroke

Understanding Stroke -- Symptoms

You should consider these symptoms warning signs and consult your health care provider: Sudden weakness or numbness in the face, arm, or leg on one side of the body. Abrupt loss of vision, strength, coordination, sensation, speech, or the ability to understand speech. These symptoms may become worse over time. Sudden dimness of vision, especially in one eye. Sudden loss of balance, possibly accompanied by vomiting, nausea, fever, hiccups, or trouble with swallowing. Sudden and severe...

Read the Understanding Stroke -- Symptoms article > >

Some surgeries (such as endarterectomy) or other procedures (such as carotid artery stenting) that are used to treat narrowed carotid arteries may cause a blood clot to break loose, resulting in a stroke.

Causes of hemorrhagic stroke

A hemorrhagic stroke is caused by bleeding in or around the brain.

  • Bleeding inside the brain itself (intracerebral hemorrhage, or ICH) may be a result of long-term high blood pressure.
  • Bleeding in the space around the brain (subarachnoid hemorrhage, or SAH) may be caused by a ruptured aneurysm or uncontrolled high blood pressure.

Other less common causes include head or neck injuries, certain diseases, and radiation treatment for cancer in the neck or brain.

WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Today on WebMD

brain illustration stroke
Know these 5 signs.
brain scans
Test your stroke smarts.
 
woman with migraine
Is there a link?
brain scan
Get the facts.
 
hand weights
Slideshow
man in silhouette and brain
Article
 
blood vessel
Article
Colored mri of brain
Article
 
senior man stretching pre workout
Article
Floor level view of therapist helping stroke patie
Article
 
concerned woman
Article
Lowering Cholesterol Slideshow
SLIDESHOW
 

WebMD Special Sections