Are our major health concerns misplaced?

It seems so, according to two recent surveys. One poll, done by the Associated Press in collaboration with LifeGoesStrong.com, found middle-aged Americans saw cancer to be the greatest health threat, followed by memory loss. And that opinion seems to cross borders: A phone survey by Alzheimer Europe of 2,700 people in Spain, Germany, Poland and the United States also found cancer to be the most worrisome disease. Alzheimer's disease was a close second in every country surveyed except Poland.

Yet neither cancer nor Alzheimer's Disease is the biggest killer of Americans. The National Center for Health Statistics says that heart disease is the deadliest health problem, killing close to 617,000 people every year. Cancer and Alzheimer's kill about 563,000 and 75,000 people, respectively.

Heart disease is also the most costly medical condition for American adults. A 2008 study, directed by the U.S. Department of Health and Human Services Agency for Healthcare Research and Quality, calculated the price tag at $90.9 billion. Cancer cost $71.4 billion and mental disorders $59.9 billion.