TUESDAY, Aug. 24 (HealthDay News) -- People who suffer migraines with aura are at increased risk of dying from heart disease and stroke, but the individual risk for a migraine sufferer is low, two new studies show.

Auras -- temporary visual or sensory disturbances that occur before or during a migraine headache -- affect about one in five migraine sufferers, according to the U.S. National Women's Health Information Center.

Both studies were published in the Aug. 25 online edition of the BMJ.

In one study, Larus Gudmundsson from the University of Iceland and colleagues examined the impact of mid-life migraines in 18,725 men and women born between 1907 and 1935 who took part in research (the Reykjavik Study) that was launched in 1967 to study heart disease in Iceland.

Based on their analysis of a 26-year follow-up of the study participants, Gudmundsson's team concluded that men and women who suffered migraine with aura were at increased risk of dying from heart disease and stroke, as well as all other causes. Those with migraine without aura were not at increased risk.

In addition, the researchers found that women with migraine with aura are also at increased risk of dying from causes other than cardiovascular disease or cancer.

The individual risk faced by migraine sufferers with aura is low and efforts to reduce their risk of heart disease-related death should focus on eliminating conventional risk factors, including high blood pressure, smoking and high cholesterol, the study authors said.

Additional research is needed to learn more about the link between migraine with aura and increased risk of death from cardiovascular disease and other causes, the team stated in a news release from the journal's publisher.

"Finally, studies are needed to determine if reducing the frequency of attacks with migraine preventive treatment might reduce the risk of cardiovascular disease," Gudmundsson and colleagues concluded.

The second study found that women who have migraines with aura are at increased risk for hemorrhagic stroke (bleeding in the brain). Hemorrhagic strokes account for about 20 percent of all strokes. However, Dr. Tobias Kurth and colleagues at the National Institute of Health and Medical Research in France said the risk remains low and further research is required to confirm their findings.

It's unclear whether doctors should inform patients about the increased risk of death associated with migraine with aura, Dr. Klaus Berger, of the University of Muenster in Germany, wrote in an editorial accompanying the first study.

Berger believes that "for many people the information will cause an unwarranted amount of anxiety, although others may use the opportunity to modify their lifestyle and risk factors accordingly."

Doctors "must carefully weigh the decision whether or not to discuss the risks related to this condition," Berger concluded.

More information

The U.S. National Women's Health Information Center has more about migraine.