Normal level of cholesterol

By Mayo Clinic staff You can lower your risk of heart disease, stroke and peripheral artery disease by keeping your cholesterol at normal levels. Here's what you need to know. What is cholesterol? Cholesterol is a waxy substance that is found in all of your cells. This substance has several useful functions including helping build your body's cells. Cholesterol comes from two sources: your liver and the foods you consume. Cholesterol travels throughout your body in your blood. Why cholesterol matters Cholesterol can join with other substances to form a thick, hard deposit on the inside of your arteries, making arteries less flexible. Eventually, these deposits grow, making it difficult for enough blood to flow through your arteries. Sometimes these deposits can break suddenly and form a blockage that causes a heart attack or stroke. However, not all cholesterol is bad. There are two types of cholesterol: • High-density lipoprotein cholesterol, or HDL HDL cholesterol is often referred to as "good" cholesterol. HDL picks up excess cholesterol in your blood and takes it back to your liver, where it is broken down and removed from your body. • Low-density lipoprotein cholesterol, or LDL LDL is the type of cholesterol that can eventually build up within the walls of your arteries, leading to a heart attack or stroke. This is why LDL is often referred to as "bad" cholesterol. When you have high cholesterol, you have too much LDL and not enough HDL in your blood, increasing your ...