A stroke occurs when there's bleeding into your brain, or normal blood flow to your brain is blocked. Within minutes of being deprived of essential nutrients, brain cells start dying — a process that may continue over the next several hours.

This is a true emergency. Seek immediate medical assistance. The sooner treatment is given, the more likely damage can be minimized. Every moment counts.

Remember: The longer a stroke goes untreated, the greater the damage and potential disability. Success of treatment may depend on how soon you receive care.

Risk factors for stroke include having high blood pressure, having had a previous stroke, smoking, having diabetes and having heart disease. Your risk of stroke increases as you age.

If you notice a sudden onset of one or more of the signs or symptoms listed below, call 911 or your local emergency number immediately:

• Sudden weakness or numbness in your face, arm or leg on one side of your body
• Sudden dimness, blurring or loss of vision, particularly in one eye
• Loss of speech or trouble talking or understanding speech
• Sudden, severe headache — a bolt out of the blue — with no apparent cause
• Unexplained dizziness, unsteadiness or a sudden fall, especially if accompanied by any of the other symptoms