Cholesterol is a waxy, fat-like substance found in your blood. Your body needs cholesterol to build healthy cells, but having high levels can increase your risk of heart disease. There are two types of cholesterol: low-density lipoprotein (LDL), often referred to as ‘bad’ cholesterol, and high-density lipoprotein (HDL), known as ‘good’ cholesterol. High cholesterol typically means you have too much LDL in your blood, which can lead to the buildup of fatty deposits in your arteries, potentially causing blockages and leading to heart attacks or strokes.