This condition is called atherosclerosis. Fat and cholesterol build up in the arteries. This buildup is called plaque. The plaque makes the arteries narrower and stiffer, and less blood can get to the heart. The condition develops slowly and may start in childhood, according to the National Heart, Lung and Blood Institute (NHLBI). It can affect the arteries of the brain, heart, kidneys and the arms and legs.

The heart and brain can be permanently damaged if they don't receive the blood they need.

As you get older, your risk increases. In men, the risk increases after age 45. In women, it increases after age 55. Your risk increases if your father or brother was diagnosed with heart disease before age 55. Your risk also increases if your mother or sister was diagnosed before age 65. These are risk factors you can control: your blood pressure, cholesterol and weight. You can cut your risk by not smoking and by getting regular exercise.

The amount of cholesterol in your blood is measured with a test called a lipoprotein profile. This test gives information about your total cholesterol. It also tells you about LDL ("bad") cholesterol, which builds up in the arteries; HDL ("good") cholesterol, which helps prevent cholesterol from building up in the arteries; and triglycerides, which can boost the risk for heart disease. Good cholesterol levels are less than 200 mg/dL for a total count; less than 100 mg/dL for LDL cholesterol; at least 40 mg/dL (the higher the better) for HDL cholesterol; and less than 150 mg/dL for triglycerides. Borderline high cholesterol levels are 200 to 239 mg/dL for a total count. High cholesterol levels are 240 mg/dL or more for a total count.

Both numbers in a blood pressure reading are important. If one or both are high, you have high blood pressure. "Prehypertension" is blood pressure between 120 and 139 for the first or top number, and between 80 and 89 for the second or bottom number. A blood pressure in this range makes it more likely that you will develop high blood pressure unless you take steps to prevent it. Doctors divide high blood pressure into two levels, Stage 1 and Stage 2. Stage 1 high blood pressure is a top number of 140 to 159 and a bottom number of 90 to 99. Stage 2 is a top number of 160 or higher and a bottom number of 100 or higher. Your heart must work harder than normal when your blood pressure is high. If this occurs for an extended time, the heart can enlarge and arteries can become scarred and hardened.

Smoking also makes it more likely for blood clots to form.

The American Heart Association (AHA) recommends that adults do 30 to 60 minutes of moderate aerobic exercise most days of the week to keep their heart healthy. Walking, running, swimming, basketball and aerobic dance are good choices. Be sure to talk to your doctor before beginning a new exercise program.

A BMI of 25 or higher means that you are overweight. A BMI of 30 or higher means that you are obese. Losing weight may help you prevent heart disease, stroke, and diabetes. Besides helping your heart, maintaining a healthy weight has many other benefits.

Too much alcohol can damage the liver and heart, lead to high blood pressure, raise triglycerides and increase weight, the NHLBI says. Moderate drinking is no more than two drinks a day for a man and no more than one drink a day for a woman. One drink is 12 ounces of beer, 5 ounces of wine or 1-1/2 ounces of 80-proof spirits. The AHA said in 2005, however, that one to two drinks per day can raise HDL ("good") cholesterol by about 12 percent. This extra HDL cholesterol can remove some of the LDL cholesterol. It can also decrease hardening of the arteries. If you don’t drink alcohol, don’t start drinking to get the benefits of alcohol. You can get same the benefits through exercise and a healthy diet.

Call 911 immediately if you or someone you're with has these symptoms. Keep in mind, however, that women and elderly adults may not have any chest pain with a heart attack. Women, for instance, are more likely to have nausea and feel pain high in the abdomen. Women who are having a heart attack also may feel extremely tired after exercise.