When you see a doctor for the first time, there are sheaves of paperwork to fill out. One question you are usually asked about is family medical history. But if you've been with the same doctor for years, your family's history may need updating.

A study published in the American Heart Association journal Circulation: Cardiovascular Genetics concluded that if you have a sister or brother who suffered a stroke, your risk of stroke is as much as 64 percent higher than if none of your siblings had a stroke. If your sibling had a stroke at age 55 or younger, your risk rises by 94 percent.

advertisement | advertise on newsday

The researchers said the reasons may not be entirely genetic. They noted that poor diet and lifestyle habits that contribute to strokes often run in the same family.

The take-away: If you have a sibling who had a stroke, tell your doctor.