When blood flow to the brain is cut off, the cells in the immediate area are the first to die.

But that process also gives off toxic chemicals that proceed to kill cells in the area surrounding the stroke.

Medication can be administered to restore blood flow and minimize damage, but it must be done quickly.

The American Heart Association’s recently broadened its guidelines to allow for clot-busters to be administered within four-and-a-half hours from when symptoms first occur.

If you are at risk of stroke, you must make sure that you, and the people you live or work with, know how to recognize the warning signs of a stroke, including:

• Sudden numbness or weakness of face, arm, or leg, especially concentrated on one side

• Sudden confusion, trouble speaking or understanding speech

• Sudden trouble seeing in one or both eyes

• Sudden dizziness, loss of balance or coordination, trouble walking

• Sudden severe headache with no known cause

If you notice these symptoms, call 911 immediately. When you arrive at the hospital, make sure the doctors know that you may be having a stroke.

Stroke-specific treatment must be administered as quickly as possible.