The traditional stroke symptoms are well known and include a sudden onset of numbness or weakness on one side of the body, trouble talking, loss of vision, or coordination problems.

But in women, doctors and bystanders should be paying attention to something else, says Lynda Lisabeth, Ph.D., MPH, researcher in the department of neurology at the University of Michigan Health System.

"What we're finding is that women experience what is considered non-traditional symptoms," said Lisabeth, who presented research findings on acute stroke symptoms at the 2009 International Stroke Conference this spring. "The non-traditional symptom that stood out was altered mental status, meaning confusion, disorientation or a loss of consciousness."

Symptoms such as sudden numbness of the face, arm or leg are a warning sign of what's happening in the body during a stroke which is a loss of blood supply to the brain because of a blocked or ruptured artery.

While larger scale studies focusing on stroke in women are warranted, the gender differences U-M researchers identified may contribute to delay in treatment for women and could signal a need to change public health campaigns, Lisabeth says.

The U-M study examined ischemic strokes, the kind experienced by 80 percent of stroke victims, and transient ischemic attack, called mini-strokes because symptoms go away quickly. Researchers examined the cases of 461 men and women and classified their symptoms as either traditional or non-traditional.

Altered mental status was the most common non-traditional symptom and it was more likely to be reported in women, the study showed. Researchers do not know why women's symptoms were different.

But the differences in symptoms may have consequences if slow recognition of stroke signs cause a delay in treatment, the researcher says.

"The only treatment that is currently FDA approved in the United States for stroke is tPA (tissue plasminogen activator), or what we call a clot-busting drug," Lisabeth says. "To administer tPA, people with stroke have to get to the hospital within three hours of symptom onset. So any delay on the part of actually getting to the hospital or delays once at the hospital could literally mean the difference between getting the therapy, or not getting the therapy."

Each year 800,000 Americans experience a stroke. Hispanic Americans and African Americans have a greater risk having a stroke, and to die from it. Intensive rehabilitation can help some overcome loss of function, but stroke remains a leading cause of disability. It is the third leading cause of death.