Stroke has traditionally been considered a health danger for middle-aged people, but research shows that if you are younger than 55 your risk of a stroke is rising significantly.

Researchers examined a database of 1.3 million adults in America to find the number who suffered strokes from 1993 to 1994 and from 1999 to 2005. They focused specifically on adults between the ages of 20 and 54.

The average age of someone who suffered a stroke fell from 71 about 20 years ago to age 69 in 2005. The researchers also found that 13 percent of stroke sufferers were between 20 and 54 years old during 1993 and 1994, but that proportion climbed to 19 percent in 2005.

The researchers note that the increase in stroke among younger Americans shows that Americans’ heart health is deteriorating.

“The reasons for this trend could be a rise in risk factors such as diabetes, obesity and high cholesterol,” writes study author Dr. Brett Kissela, a professor of neurology at the University of Cincinnati College of Medicine in Ohio. “Regardless, the rising trend found in our study is of great concern for public health.”

Strokes are the fourth leading cause of death for Americans. Of the 795,000 Americans who suffer a stroke in 2012, about 137,000 will lose their lives. But medical professionals say that lifestyle changes can greatly reduce stroke risk.

“The good news is that some of the possible contributing factors to these strokes can be modified with lifestyle changes, such as diet and exercise,” says Kissela. “However, given the increase in stroke among those younger than 55, younger adults should see a doctor regularly to monitor their overall health and risk for stroke and heart disease.”