Cholesterol is a waxy fatlike substance that your body needs to function normally. Cholesterol is naturally present in cell walls or membranes everywhere in the body, including the brain, nerves muscles, skin, liver, intestines and heart.
Your body uses cholesterol to produce many hormones, vitamin D, and the bile acids that help to digest fat. It takes only a small amount of cholesterol in the blood to meet these needs. If you have to much cholesterol in your bloodstream, the excess may be deposited in arteries, including the coronary (heart) arteries, where it contributes to the narrowing and blockages that cause the signs and symptoms of heart disease.
A simple blood test checks for high cholesterol. Simply knowing your total cholesterol level is not enough. A complete lipid profile measures your LDL (low-density lipoprotein, the bad cholesterol), total cholesterol, HDL (high density lipoprotein, the good cholesterol), and triglycerides, another fatty substance in the blood. Government guidelines say healthy adults should have this analysis every 5 years.