Age
The longer you live, the more time plaque has been building up in your arteries. 

Weight
Excess weight increases the strain on the heart, and raises blood pressure and blood cholesterol. 

Smoking

Tobacco use constricts the arteries and hinders blood flow to the heart. 

Eating
Saturated fat causes weight gain and leads to buildup of plaque in the arteries. A diet high in antioxidants reduce risk of heart attack. 

Blood Pressure

High blood pressure increases the workload of the heart. 

Cholesterol
A high level of cholesterol in the blood leads to buildup on the walls of the arteries.  Blood flow to the heart can be slowed down or blocked. 

Exercise 
Regular exercise keeps body weight, blood pressure and cholesterol under control. 

Stress
Chronic stress leads to high blood pressure. 

Family History
An individual's risk is greater if family members have suffered from heart attacks. 
 

Heart disease will kill one third of American women, and even more American men which makes it the leading cause of death in the U.S.

Though men tend not to worry about heart problems until they are in their 40s, artery blockage can be detected when men are in their mid-20s and most men can decrease their risk by changing their lifestyle.

The Mayo Clinic's Dr. Scott Wright says that too many young men underestimate the dangers. "The biggest problem I see is denial — that it can be me, that what I'm doing today in 20 or 30 years can lead to having heart disease, being at risk for heart attack, or needing bypass surgery."

Men's Health Magazine and 20/20 studied the habits and history of three regular guys: a police officer, a student and a fireman. Who do you think is most likely to have a heart attack? You can find out by watching 20/20 tonight.