Cholesterol is a soft, fat-like, waxy substance found in the bloodstream and in all of your body's cells.

Cholesterol plays a critical role in health because it is used to produce cell membranes and some hormones and serves other needed bodily functions.

But too much cholesterol in the blood is a major risk for coronary heart disease, which leads to heart attack. It's also a risk factor for stroke. Hypercholesterolemia is the term for high levels of blood cholesterol.

The human body produces the majority of cholesterol naturally, based on heredity, and the rest comes from cholesterol in animal products like meat, poultry, fish, eggs, butter, cheese and whole milk.

Food from plants — like fruits, vegetables and some cereals — doesn't have cholesterol. Some foods that don't contain animal products may contain trans fats, which cause your body to make more cholesterol. Foods with saturated fats also cause the body to make more cholesterol.

Since cholesterol and other fats can't dissolve in the blood, they are transported to and from the cells by lipoproteins.

Low-density lipoprotein, or LDL, is known as the "bad" cholesterol. Too much LDL cholesterol can clog arteries, increasing the risk of heart attack and stroke.

High-density lipoprotein, or HDL, is known as the "good" cholesterol. The body makes HDL cholesterol for your protection. It carries cholesterol away from your arteries. Studies suggest high levels of HDL cholesterol reduce the risk of heart attack.