Cholesterol

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 Ð'-- like fruits, vegetables and cereals Ð'-- 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.) Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe that HDL removes excess cholesterol from plaque in arteries, thus slowing the buildup.

What is Lp(a) cholesterol?

Lp(a) is a genetic variation of plasma LDL. A high level of Lp(a) is an important risk factor for developing fatty deposits in arteries prematurely. The way an increased Lp(a) contributes to disease isn't understood. The lesions in artery walls contain substances that may interact with Lp(a), leading to the buildup of fatty deposits.

The triglyceride connection

Triglyceride is a form of fat. It comes from food and is also made in your body. People with high triglycerides often have high total cholesterol, high LDL cholesterol and a low HDL cholesterol level. Many people with heart disease also have high triglyceride levels. People with diabetes or who are obese are also likely to have high triglycerides. Triglyceride levels of less than 150 mg/dL are normal; levels from 150-199 are borderline high. Levels that are borderline high or high (200 mg/dL to 499 mg/dL) may need treatment in some people. Triglyceride levels of 500 mg/dL or above are very high. Doctors need to treat high triglycerides in people who also have high LDL cholesterol levels.

What Are Healthy Levels of Cholesterol?

Your total blood cholesterol level

your total blood cholesterol will fall into one of these categories:

Desirable Ð'-- Less than 200 mg/dL

Borderline high risk Ð'-- 200Ð'-239 mg/dL

High risk Ð'-- 240 mg/dL and over

Here is some more explanation about each of these categories.

Desirable

If your total cholesterol is less than 200 mg/dL, your heart attack risk is relatively low, unless you have other risk factors. Even with a low risk, it's still smart to eat foods low in saturated fat and cholesterol, and also get plenty of physical activity. Have your cholesterol levels measured every five years Ð'-- or more often if you're a man over 45 or a woman over 55.

Borderline high risk

People whose cholesterol level is from 200 to 239 mg/dL are borderline high risk. About a third of American adults are in this (borderline) group; almost half of adults have total cholesterol levels below 200 mg/dL.

Have your cholesterol and HDL rechecked in one to two years if:

Your total cholesterol is in this range.

Your HDL is less than 40 mg/dL.

You don't have other risk factors for heart disease.

You should also lower your intake of foods high in saturated fat and cholesterol to reduce your blood cholesterol level to below 200 mg/dL. Your doctor may order another blood test to measure your LDL cholesterol. Ask your doctor to discuss your LDL cholesterol with you. Even if your total cholesterol is between 200 and 239 mg/dL, you may not be at high risk for a heart attack. Some people Ð'-- such as women before menopause and young, active men who have no other risk factors Ð'-- may have high HDL cholesterol and desirable LDL levels. Ask your doctor to interpret your results. Everyone's