Unhealthy blood cholesterol levels are one of the major risk factors for heart disease — the number one killer of American adults. Understanding how cholesterol affects your health starts with understanding HDL and LDL.

HDL stands for High Density Lipoprotein. That’s the good cholesterol. HDL carries cholesterol away from the artery walls to the liver where it can be removed from the blood stream. A high HDL level appears to protect against heart disease.

LDL stands for Low Density Lipoprotein. That’s the bad cholesterol. Too much LDL in the blood can lead to a build-up of cholesterol deposits within the walls of the arteries that lead to the heart, brain and legs. This is referred to as “atherosclerosis” or narrowing of the inside of the arteries. A narrowed artery can block the flow of blood and cause a heart attack, stroke or gangrene in the legs and feet.

It is important to keep a healthy ratio of HDL to LDL. A low LDL level can help lower the ratio. To check your cholesterol level, ask your doctor for an HDL/LDL inventory.