Cholesterol is a soft, fat-like, waxy substance found in the bloodstream and in all your body's cells. It's normal to have cholesterol. It's an important part of a healthy body because it's used for producing cell membranes and some hormones, and serves other needed bodily functions. But too high a level of cholesterol in the blood is a major risk for coronary heart disease, which leads to heart attack. It's also a risk factor for stroke. Hypercholesterolemia is the term for high levels of blood cholesterol.
You get cholesterol in two ways. Your body makes some of it, and the rest comes from cholesterol in animal products that you eat, such as meats, poultry, fish, eggs, butter, cheese and whole milk. Food from plants — like fruits, vegetables and cereals — doesn't have cholesterol. Some foods that don't contain animal products may contain trans-fats, which cause your body to make more cholesterol. Foods with saturated fats also cause the body to make more cholesterol.
Cholesterol and other fats can't dissolve in the blood. They have to be transported to and from the cells by special carriers called lipoproteins. There are two kinds that you need to know about. Low-density lipoprotein, or LDL, is known as the "bad" cholesterol. Too much LDL cholesterol can clog your arteries, increasing your risk of heart attack and stroke. High-density lipoprotein, or HDL, is known as the "good" cholesterol. Your body makes HDL cholesterol for your protection. It carries cholesterol away from your arteries. Studies suggest that high levels of HDL cholesterol reduce your risk of heart attack.
What's the Difference Between LDL and HDL Cholesterol?
Why LDL cholesterol is considered "bad"?
When too much LDL 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 clog those arteries. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, it can cause a heart attack or stroke. The levels of HDL cholesterol and LDL cholesterol in the blood are measured to evaluate the risk of having a heart attack. LDL cholesterol of less than 100 mg/dL is the optimal level. Less than 130 mg/dL is near optimal for most people. A high LDL level (more than 160 mg/dL or 130 mg/dL or above if you have two or more risk factors for cardiovascular disease) reflects an increased risk of heart disease. That's why LDL cholesterol is often called "bad" cholesterol.
Why HDL cholesterol is considered "good"?
About one-third to one-fourth of blood cholesterol is carried by high-density lipoprotein (HDL). HDL cholesterol is known as the "good" cholesterol because a high level of it seems to protect against heart attack. (Low HDL cholesterol levels [less than 40 mg/dL] increase the risk for heart disease.)...