While Americans suffered fewer strokes overall from 2000 to 2010, stroke rates climbed substantially among younger adults and blacks, a new study found.

Hospitalizations for strokes caused by artery blockages dropped 18.4 percent overall during the decade, with greater decreases among the elderly, University of Southern California researchers found.

Within the overall decrease, however, some groups saw an increase in hospitalizations as the burden of stroke shifted to younger adults. For example, although stroke hospitalizations dropped 50 percent for people 65 and older, they increased nearly 49 percent among 25- to 64 year-olds.

Stroke hospitalizations also varied by race -- up almost 14 percent among blacks.

Dr. Paul Wright, chair of neurology at North Shore University Hospital, in Manhasset, N.Y., said, "There are things we can do to help prevent strokes." Topping the list: living a healthier lifestyle, which can prevent as many as 80 percent of strokes, said Wright, who was not involved with the study.

The study authors said better control of blood pressure, blood sugar and cholesterol probably accounted for the steep decline in strokes among the elderly.

Exactly why strokes are up among younger adults isn't clear, but more awareness of stroke symptoms is the most likely reason, Wright said.

"People are more aware of the risk factors for stroke and seek help when something happens, as opposed to saying, 'I'm getting a little numbness and tingling and weakness, but it will go away,' " he said. "So people are more likely to get help sooner."

Wright believes the higher stroke rate among blacks is largely due to lack of access to care. He also cited a need for more stroke education targeted to this population.

Dr. Amytis Towfighi, senior researcher on the study, emphasized the protective role of lifestyle behaviors in stroke prevention.

"The majority of cardiovascular events including heart attacks and stroke can be prevented through changing seven modifiable risk factors, namely: smoking, obesity, physical inactivity, poor diet, cholesterol, blood pressure and blood sugar," she said.

If you've had a stroke, "it's not too late to change your lifestyle. By making immediate changes one is on the road to a longer, healthier life," said Towfighi, an assistant professor of neurology at USC's Keck School of Medicine.

Healthier lifestyle habits probably accounted for the hefty decline in strokes for seniors -- down 28 percent for those 65 to 84, and more than 22 percent for those 85 and older, Towfighi said.

For the study, Towfighi and her colleagues analyzed data from a national database that collects information on about 8 million hospital stays each year.

They looked at the most common type of stroke, called ischemic stroke. This occurs when a clot in a blood vessel in the brain cuts off the blood supply to that area. Symptoms usually include weakness or numbness and tingling on one side of the body.

The researchers found that stroke hospitalization for whites declined about 12 percent and for Hispanics nearly 22 percent. But it rose 13.7 percent among blacks.

Overall, women saw a steeper decline in stroke than men -- more than 22 percent versus roughly 18 percent.

The study findings were published online May 11 in the Journal of the American Heart Association.