Certain factors, called coronary risk factors, increase your risk of a heart attack. These factors contribute to the unwanted buildup of deposits (atherosclerosis) narrowing arteries including those to your heart. Coronary risk factors include:
Smoking and long-term exposure to secondhand smoke damage the interior walls of arteries — including arteries to your heart — allowing deposits of cholesterol to collect and hamper blood flow. Smoking also increases the risk of deadly blood clots forming and causing a heart attack.
High blood pressure
Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. Over time, high blood pressure can damage arteries that feed your heart by accelerating atherosclerosis. High blood pressure can be an inherited problem. The risk of high blood pressure increases as you age, but the main culprits for most Americans are eating a diet too high in salt and being overweight.
High blood cholesterol or triglyceride levels
Cholesterol is a major part of the deposits that can narrow arteries throughout your body, including those that supply your heart. A high level of the wrong kind of cholesterol in your blood increases your risk of a heart attack. Low-density lipoprotein, or LDL, cholesterol (the "bad" cholesterol) is most likely to narrow arteries. A high LDL level is undesirable and is often a byproduct of a diet high in saturated fats and cholesterol. A high level of triglycerides, a type of blood fat related to your diet, also is undesirable. However, a high level of high-density lipoprotein (HDL) cholesterol (the "good" cholesterol), which helps the body clean up excess cholesterol, is desirable and lowers your risk of heart attack.
Lack of physical activity
An inactive lifestyle contributes to high blood cholesterol levels and obesity. Conversely, people who get regular aerobic exercise have better cardiovascular fitness, which decreases their overall risk of heart attack. Exercise is also beneficial in lowering high blood pressure.
Obesity involves having a high proportion of body fat. Obesity raises the risk of heart disease because it's associated with high blood cholesterol levels, high blood pressure and diabetes.
Diabetes is the inability of your body to properly produce or respond to insulin. Insulin, a hormone secreted by your pancreas, allows your body to use glucose, which is a form of sugar from foods. Diabetes can occur in childhood, but it appears more often in middle age and among overweight people. Diabetes greatly increases the risk of a heart attack by speeding up atherosclerosis and negatively affecting blood cholesterol levels.
You may respond to stress in ways that can increase your risk of a heart attack. If you're under stress, you may overeat or smoke from nervous tension. Too much stress or anger can also raise your blood pressure.
Consumed in moderation, alcohol helps raise HDL levels — the "good" cholesterol — and can have a protective effect against heart attack. Excessive drinking can raise your blood pressure and triglyceride levels, increasing your risk of heart attack.
Family history of heart attack
If your siblings, parents or grandparents have had early heart attacks, you too may be at risk. Your family may have a genetic condition that raises unwanted blood cholesterol levels. High blood pressure can also run in families. In addition, families who practice or promote poor health habits such as smoking or eating high-fat diets may contribute to coronary artery disease.
Homocysteine, C-reactive protein and fibrinogen
Studies show that people who have higher levels of homocysteine, C-reactive protein and fibrinogen appear to be at increased risk of heart disease. These factors have only recently been identified as cardiovascular disease risk factors and can be reduced with folic acid supplements and a healthy diet. By modifying smoking, eating and exercise (lack of) habits, Fibrinogen and C-reactive protein levels may be reduced.
While reducing or eliminating risk factors can reduce your chance of having a first or a second heart attack, risk factors such as heredity and gender cannot be eliminated. Men are generally at greater risk to have a heart attack than women. For women the risk increases after menopause and usually after age 55. If your father had heart disease before age 55 or your mother before age 65, you are at greater risk for developing heart disease.