Cholesterol Testing and the Lipid Panel
Why get a cholesterol test? For decades, doctors have known that people with high total cholesterol levels are at higher risk for heart disease. More recently, they've found the different forms of cholesterol ("good" and "bad") also affect risk.
Knowing your cholesterol levels is an essential part of understanding your own risk for heart disease. The American Heart Association recommends that everyone over age 20 get a cholesterol test.
Cholesterol Tests: the Good, Bad, the Fatty
Cholesterol is a form of fat that's not all bad -- a certain amount is essential for life. Cholesterol helps provide stability to the outer membranes of our bodies' cells.
But cholesterol can have harmful effects. LDL -- or "bad" -- cholesterol can deposit in blood vessel walls. Over years, LDL cholesterol and other substances clog arteries in the process called atherosclerosis. Arteries in the heart narrowed by atherosclerosis can then develop sudden blood clots, causing heart attacks.
Having high total cholesterol, high bad cholesterol, or low good cholesterol could place you at higher than average risk for heart disease. Knowing about high cholesterol is the first step toward lowering it, which reduces your risk. That's the reason to get a cholesterol test.
An Overview of Cholesterol Tests
There are multiple forms of cholesterol circulating in the blood. The various forms of cholesterol and other fats in the blood are together called lipids. Doctors measure and diagnose high cholesterol with a simple blood test, often called a lipid profile. It's often done after fasting for nine to 12 hours to eliminate the contribution of any fat you recently ate.
Tests for cholesterol provide results for four different types of lipids.
- Total cholesterol
- LDL (low-density lipoprotein), the "bad cholesterol"
- HDL (high-density lipoprotein), the "good cholesterol"
- Triglycerides, another form of fat in the blood
Some lipid panels provide more detailed information, with information on the presence and sizes of various fat particles in the blood. Research is ongoing into the possible contribution to heart disease of these factors. Currently, there is no consensus on when more advanced testing of fat particle size is necessary.