What is a stroke?

A stroke results when blood and oxygen flow to the brain is stopped or interrupted. This happens because of a ruptured or blocked blood vessel.

Doctors may use the terms cerebrovascular accident (CVA), cerebral infarction or brain attack to describe stroke.

The role of your brain and central nervous system

Special nerve cells in the brain -- neurons -- send signals to the rest of your body. These signals control your speech, movement, thinking process and senses (hearing, sight and touch).

The left side of your brain controls the right side of your body. Usually, the left side of your brain controls the way you talk and understand speech. The right side of your brain controls the left side of your body.

The side of your brain affected by a stroke determines which parts of your body are affected. The base of your brain (brainstem) is connected to your spinal cord. The brainstem controls your eye movements, swallowing, breathing, alertness and other specialized functions.

Without oxygen and other nutrients in your blood, neurons can be damaged and may die. When that happens, you may not be able to talk, understand or use your arms or legs.