Coronary heart disease, or CHD, occurs when cholesterol and fat deposits build up inside the walls of the arteries that supply oxygen-rich blood to your heart. As the arteries narrow, your heart is deprived of oxygen and nutrients. High blood cholesterol is one of the most important risk factors for CHD and heart attack, says the National Heart, Lung and Blood Institute, or NHLBI.
Identification
Cholesterol is a fatty substance that doesn't dissolve in your blood, so it needs carriers called lipoproteins to move it around the body and into the cells. Low-density lipoprotein, or LDL, is known as the "bad" cholesterol, while high-density lipoprotein, or HDL, is the "good" cholesterol. Total cholesterol refers to a combination of HDL, LDL, triglyceride fats and Lp(a) cholesterol, a genetic variation of LDL, says the American Heart Association.
Sources
Your liver produces about 75 percent of the cholesterol in your blood, while the remaining 25 percent comes from the foods you eat, states the American Heart Association. When you eat foods containing cholesterol or saturated fat, your blood levels rise.
Effects
If you have extra LDL cholesterol in your blood, it slowly builds up inside the walls of the arteries to create a thick, hard deposit called plaque. Your arteries become more rigid, a condition known as atherosclerosis. When one of these plaques breaks off and blocks one or more of the arteries supplying your heart, it can cause a heart attack. While experts don't fully understand how HDL cholesterol works, many believe it carries cholesterol out of the bloodstream to the liver to be passed out of your body. Other experts think HDL cholesterol removes cholesterol from the plaque on the blood vessel wall, says the American Heart Association.
Considerations
Because high blood cholesterol doesn't cause any symptoms, you won't know your numbers are elevated unless your doctor orders a blood test. According to the NHLBI, a desirable total cholesterol level is below 200 mg/dL, while an optimal LDL level is below 100 mg/dL. HDL levels of 60 mg/dL or above reduce your risk for heart disease, while those below 40 mg/dL increase your risk of developing CHD.
Prevention/Solution
While you can't change the genes that regulate cholesterol production, you can make lifestyle choices that lower blood cholesterol and reduce your risk of heart disease. NHLBI recommends the therapeutic lifestyle changes, or TLC, diet that's low in saturated fats and cholesterol. Increase your level of physical activity, NHLBI says, lose weight if you're overweight or obese and take cholesterol-lowering medications called statins if your doctor has prescribed them for you.
