High cholesterol is one of the major controllable risk factors for coronary heart disease, heart attack and stroke. As your blood cholesterol rises, so does your risk of coronary heart disease. If you have other risk factors (such as high blood pressure or diabetes) as well as high cholesterol, this risk increases even more. The more risk factors you have, the greater your chance of developing coronary heart disease. Also, the greater the level of each risk factor, the more that factor affects your overall risk.
When too much LDL (bad) cholesterol circulates in the blood, it can slowly build up in the inner walls of the arteries that feed the heart and brain. Together with other substances, it can form plaque, a thick, hard deposit that can narrow the arteries and make them less flexible. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, a heart attack or stroke can result.
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