Cholesterol is a waxy substance. Our body needs it to build cells and make vitamins, hormones. But in excess it can cause problem.
HDL Cholesterol: Good cholesterol. High levels seem to protect against heart diseases, and low levels indicate a greater risk of heart diseases.
LDL Cholesterol: Bad cholesterol. Simply deposits in the blood, leading to build up plaque in your arteries. High levels mean an increased risk of heart diseases.