The World Health Organization estimates that 17 million people die every year of cardiovascular disease, and of heart attacks and stroke in particular. Strokes are caused by a blockage in the blood supply to the brain either by a clot or a broken blood vessel. Most symptoms of stroke ar obvious, But the "silent stroke" often goes undiagnosed.

Most strokes are readily apparent by common symptoms such as

Exercise can help in preventing strokes

weakness, numbness, confusion, loss of balance or severe headache. But recent studies show that many people experience strokes with no recognizable symptoms, There are called "silent strokes" and they frequently are not recognized either by the patient or the doctor.

As many as 600-thousand Americans are diagnosed with the more obvious forms of stroke, But a recent study of 16-thousand people indicates that silent strokes are also common. At least one in three older people from age 70 on are believed to experience a silent stroke every year.

In another study, younger women who frequently suffer from migraine headaches, combined with the visual symptoms of flashing light or spots, are also at higher risk for stroke. This type of headache is called "migraine with aura."

stroke patient having trouble reaching bottle

Women with aura migraines who smoke and use birth control pills are seven times more likely to have a stroke in the future, Researchers say they could reduce those odds by eliminating cigarettes and adopting a healthier lifestyle.