In addition to disrupting daily life for the millions of Americans who suffer from migraine headaches, researchers at Johns Hopkins have confirmed that migraines raise the risk of ischemic stroke by 230 percent.

Ischemic stroke, which is the most common type of stroke, occurs when blood supply to the brain is suddenly cut off by plaque or a blood clot.

The researchers pooled results of 21 studies involving 622,381 North American and European men and women between the ages of 18 and 70. None had suffered a stroke prior to the beginning of the study. The researchers found that those who experienced aura, flashing lights, zigzag lines, and blurred side vision, had an even higher risk of stroke—2.5 times higher in men and 2.9 times higher in women.

"Identifying people at highest risk is crucial to preventing disabling strokes," Saman Nazarian, M.D., an assistant professor at the Johns Hopkins University School of Medicine, said in a statement. "Based on this data, physicians should consider addressing stroke risk factors in patients with a history or signs of light flashes and blurry vision associated with severe headaches."

Nazarian suggests migraine sufferers lower their risk by stopping smoking and by taking blood pressure medication and blood-thinning medications such as aspirin. He suggests women consider not using oral contraceptives or hormone replacement therapy since hormone drugs may explain their higher risk.

As many as 10 percent of American suffer from migraines and women outnumber men three to one.