Most people with high cholesterol are not sure how to manage the potentially deadly condition, according to a survey from the American Heart Association.

Nearly one in three American adults has high levels of LDL cholesterol, according to AHA statistics. It’s a serious health risk, because too much LDL — or “bad” — cholesterol can result in narrowed arteries and cause clots that can lead to a heart attack or stroke.

The survey was conducted as part of the AHA’s Check. Change. Control. Cholesterol initiative. Participants included nearly 800 people with a history of heart disease or at least one major risk factor, such as high blood pressure, high cholesterol or diabetes.

Read more at the AHA