Cholesterol is essential for life. A fat-like substance produced by the liver and found in all your cells, it is used to form cell membranes, and to manufacture hormones, bile acids and Vitamin D.
Dietary cholesterol is found only in foods that come from animals. Concentrated sources in foods include egg yolks, organ meats, fatty meats, and whole milk dairy products. Your body produces cholesterol even if you do not take in cholesterol through your diet.
The problem occurs when you have too much cholesterol in your body.
A measurement of your cholesterol level includes LDL cholesterol (bad cholesterol), HDL cholesterol (good cholesterol), and triglycerides.
LDL-Cholesterol: the "Bad" Cholesterol
When a person has too much LDL-cholesterol in the blood, it can slowly build up on the inner walls of the arteries which feed the heart and brain. Together with other substances it can form plaque, a thick, hard coating that can clog the arteries. A high LDL-cholesterol level increases your risk of heart attack. An LDL level between 130 and 160 is considered borderline risk, and an LDL level over 160 is considered a high risk. Most patients with coronary artery disease should have an LDL cholesterol below 100. Usually patients will require medication to achieve this level of LDL.
HDL-Cholesterol: the "Good" Cholesterol
HDL-cholesterol carries cholesterol away from the bloodstream and back to the liver, where it is passed from the body. A high level of HDL seems to protect against heart attack, and a low level indicates a greater risk. HDL-cholesterol levels range from 40 to 50 mg/dl in the average man; from 50 to 60 mg/dl in the average woman. HDL-cholesterol less than 35 mg/dl is considered low. The most common treatable causes of low HDL-cholesterol are cigarette smoking, being overweight and being physically inactive.
Triglycerides
Triglycerides are the chemical form in which most fats exist. Blood triglyceride levels above 200 mg/dl are considered high, and may also play a role in forming plaque. Being overweight, drinking large amounts of alcohol or having diabetes can cause high blood triglycerides.
How can I lower my blood cholesterol level?
Most people can lower their blood cholesterol levels by following a diet that is low in saturated fat and cholesterol. Other lifestyle factors that can improve cholesterol levels include aerobic exercise, losing weight if overweight and not smoking. Beyond diet alone, many patients benefit from treatment with medications designed to lower cholesterol.