WEIRD: Strokes recently declined among men, but not women, study says.

In 2013, Diana Hardeman was 30 years old. She was a vegetarian, a non-smoker, a surfer and the picture of health — until she had a stroke.

“The paralysis ended up seeping down from my arm to my leg, leaving the whole right side of my body basically immobile,” Hardeman said. “I thought maybe I’m becoming paralyzed or potentially seeing death.”

“It was terrifying,” she said.

Hardeman is an example of a puzzling and concerning trend. A study released Wednesday found that from 1999 to 2005, the incidence of stroke declined in both men and women. But from 2005 to 2010, while the rates among men continued to drop, they stayed the same for women.

Dr. Kathryn Rexrode of Boston’s Brigham and Women’s Hospital said risk factors for stroke — such as obesity, high blood pressure, an irregular heartbeat and diabetes — may for some reason affect women differently than men.

“Diabetes is a strong risk factor for stroke in both men and women, but in women the risk is 26 percent higher than in men with diabetes,” Rexrode said.