Cholesterol 101

Pfizer, the world's largest drug maker, told more than 100 trial investigators to stop giving patients the drug, called torcetrapib. The cholesterol drug was intended to treat heart disease, but it actually caused an increase in deaths and heart problems.

What is cholesterol?

Cholesterol is a waxy substance produced by the body and found in foods that come from animals. Cholesterol is needed by your body to make hormones, skin oils, digestive juices and vitamin D. You could not live without some cholesterol in your body.

How does high cholesterol cause heart disease?

According to WebMD, when there is too much cholesterol in your blood, it builds up in the walls of your arteries. Over time, this buildup causes the arteries to harden -- a process called atherosclerosis. The arteries become narrowed and blood flow to the heart muscle is slowed down or blocked. The blood carries oxygen to the heart, and if enough blood and oxygen cannot reach your heart, you may suffer chest pain. If the blood supply to a portion of the heart is completely cut off by a blockage, the result is a heart attack.

How do good and bad cholesterol differ?

Low-density lipoprotein (LDL or "bad" cholesterol) and high-density lipoprotein (HDL or "good" cholesterol.) are the two types of cholesterol. These are the forms in which cholesterol travels in the blood. LDLs have little protein and high levels of cholesterol and HDL has a lot of protein and very little cholesterol.

What are the symptoms of high cholesterol?

High cholesterol itself does not cause any symptoms so many people are unaware that their cholesterol levels are too high. Therefore, it is important to find out what your cholesterol numbers are because lowering cholesterol levels that are too high lessens the risk for developing heart disease and reduces the chance of a heart attack or dying of heart disease, even if you already have it.

What are statins?

Statins block the production of cholesterol in the liver itself. They lower LDL, the "bad" cholesterol, and triglycerides and have a mild effect in raising HDL, the "good" cholesterol. These drugs are the first line of treatment for most people with high cholesterol. Side effects can include intestinal problems, liver damage, and in a few people, muscle tenderness or weakness.

Are there foods to avoid while taking cholesterol medicine?

Ask your doctor about the other medications you are taking, including herbals and vitamins, and their impact on cholesterol-lowering medications. WebMD advises that you should not drink grapefruit juice while taking cholesterol-lowering drugs, as it can interfere with the liver's ability to metabolize these medications.

• Click here for more information from WebMD.

• The Food and Drug Administration.

• Read more about the Torcetrapib trial from Pfizer.

• Click here to read more from the American Heart Association.