Cholesterol

Cholesterol isn't entirely the health villain it's made out to be, its name darkly linked to heart attack, stroke, and other types of cardiovascular disease. Our bodies need cholesterol, which is a type of lipid (another name for fat) to make cell membranes, key hormones like testosterone and estrogen, the bile acids needed to digest and absorb fats, and vitamin D. Cholesterol is so important to the body that the liver and intestines make it from scratch.

What is "bad" about cholesterol isn't the substance itself — in fact, we can't live without it — but how much of it is in the bloodstream.

The body packages cholesterol in two main particles: low-density lipoprotein (LDL), the so-called bad cholesterol, and high-density lipoprotein (HDL), the so-called good cholesterol. Too much LDL in the bloodstream helps create the harmful cholesterol-filled plaques that grow inside arteries. Such plaques are responsible for angina (chest pain with exertion or stress), heart attacks, and most types of stroke.

What causes a person's LDL level to be high? Most of the time diet is the key culprit. Eating foods rich in saturated fats, trans fats, and easily digested carbohydrates boost LDL. Genes are sometimes at the root of high cholesterol, and some medications can boost LDL.

If you have high cholesterol, making changes in your diet can help bring it down into the healthy range. Exercise can help boost the level of protective HDL. Several types of medication, notably the family of drugs known as statins, can powerfully lower LDL. Depending on your cardiovascular health, your doctor may recommend taking a statin.

Cholesterol Articles

High Cholesterol (Hypercholesterolemia)

Cholesterol is a fatty substance that occurs naturally in the body. It performs several vital functions. It is needed to make the walls surrounding the body's cells and is the basic material that is converted to certain hormones. Your body makes all the cholesterol you need. You need only a small amount of fat in your diet to make enough cholesterol to stay healthy. The fat and cholesterol you eat are absorbed in the intestine and transported to the liver. The liver converts fat into cholesterol, and releases cholesterol into the bloodstream. There are two main types of cholesterol: low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) and high-density lipoprotein (HDL) cholesterol (the "good" cholesterol). High levels of LDL cholesterol are linked to atherosclerosis, which is the accumulation of cholesterol-rich fatty deposits in arteries. This can cause arteries to narrow or become blocked, slowing or stopping the flow of blood to vital organs, especially the heart and brain. Atherosclerosis affecting the heart is called coronary artery disease, and it can cause a heart attack. When atherosclerosis blocks arteries that supply blood to the brain, it can cause a stroke. (Locked) More »

Arterial Blood Flow Studies of the Legs (Segmental Doppler Pressures)

People who have leg pain when exercising may need an evaluation to make sure they have normal blood flow through their leg arteries. Normally blood pressure is similar whether it is measured in the legs or in the arms. If blood pressure is lower in the legs, it usually means that cholesterol buildup inside the leg arteries is interfering with circulation. By taking accurate blood pressure measurements at different locations along your legs, your doctors can determine if you have any arterial narrowing and, if so, where. In order to get accurate blood pressure measurements, your doctor uses a technique called Doppler ultrasound. Doppler ultrasound is a painless way to detect blood flowing through a small artery. It uses sound waves and a type of sonar detection system to make noise when blood flow is detected. For arterial studies of the legs (called segmental Doppler pressures), Doppler ultrasound is used in place of the stethoscope that doctors usually use when taking blood pressures. (Locked) More »

Atherosclerosis

Atherosclerosis is a narrowing of the arteries that can significantly reduce the blood supply to vital organs such as the heart, brain and intestines. In atherosclerosis, the arteries are narrowed when fatty deposits called plaques build up inside. Plaques typically contain cholesterol from low-density lipoproteins (LDL), smooth-muscle cells and fibrous tissue, and sometimes calcium. As a plaque grows along the lining of an artery, it produces a rough area in the artery's normally smooth surface. This rough area can cause a blood clot to form inside the artery, which can totally block blood flow. As a result, the organ supplied by the blocked artery starves for blood and oxygen. The organ's cells may either die or suffer severe damage. (Locked) More »

Coronary Artery Disease

Coronary artery disease (CAD) is the narrowing of coronary arteries. These are the blood vessels that supply blood and oxygen to the heart. The condition is also called coronary heart disease (CHD). CAD is usually caused by atherosclerosis. Atherosclerosis is the buildup of plaque inside the coronary arteries. These plaques are made up of fatty deposits and fibrous tissue. (Locked) More »

Abdominal obesity and your health

Excess body fat has serious consequences for health. It' associated with high levels of LDL ("bad") cholesterol and triglycerides and low levels of HDL ("good") cholesterol. It impairs the body's responsiveness to insulin, raising blood sugar and insulin levels. Excess body fat contributes to major causes of death and disability, including heart attacks, strokes, high blood pressure, cancer, diabetes, osteoarthritis, fatty liver, and depression. Faced with these risks, it's no wonder that you want to know how much you should weigh. But this common and important question is actually the wrong question. For health, the issue is not how much you weigh, but how much abdominal fat you have. Methods have changed over the years. But when scientists recognized that what matters is not body weight but body fat, standards began to change. The body mass index (BMI), remains enshrined as the standard way to diagnose overweight and obesity. More »

Making sense of cholesterol tests

Time to get your cholesterol checked. Okay, but which test should you get? It's not so simple anymore. Here is a rundown of some of the choices and their pros and cons: Total cholesterol. This is the simplest and least expensive test, and fasting isn't necessary. The test doesn't require any sophisticated lab work, either. The simple, do-it-yourself home cholesterol tests measure total cholesterol. If you otherwise have a low heart risk, a reading of 200 or below puts you in the desirable category; 200–239 is borderline high; and 240 or more is high. But total cholesterol includes both "good" high-density lipoprotein (HDL) cholesterol, and the "bad" varieties, chiefly low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL). So if your total cholesterol is in the desirable category, it's possible that you may have unhealthy levels of HDL (too low) and LDL and VLDL (too high). Think of total cholesterol as a first glimpse, a peek. Doctors are not supposed to make any treatment decisions based on this number alone. More »

LDL cholesterol: Low, lower, and lower still

The overall message on "bad" LDL cholesterol is much the same as it has been: Lower is better and how low your level should be depends on your cardiovascular risk factors. But the standard for what low LDL means keeps on getting lower. While  an LDL level under 70 is still the usual goal for people at the highest risk for cardiovascular disease perhaps that is still too high. The main impetus for the "lower is better" mantra got started more than 10 years ago based on studies of the statin drugs such as atorvastatin (Lipitor) and simvastatin (Zocor). The studies involved only people with heart disease, so the lessons learned don't directly apply to everyone, but there are certainly enough people with heart disease to make them important. More »