Causes of Stroke
Stroke occurs when blood flow to a region of the brain is obstructed, causing brain tissue death.
Ischemic stroke is usually caused by a blood clot in an artery that supplies blood to the brain. Introduction of a foreign substance into the bloodstream may also cause ischemic stroke. For example, an air embolism may occur in deep-sea divers who surface too quickly or may be introduced during intravenous injection.
Hemorrhagic stroke is caused by ruptured blood vessel (aneurysm), arteriovenous malformation (AVM, blood vessel defect), tumor, or traumatic brain injury.