What is cholesterol and how does it affect your body?

Cholesterol is a type of fat — or what doctors call a lipid. Cholesterol and other lipids are as necessary for humans and other animals as water or air. Cholesterol is the main component of cell membranes and other structures, a kind of building block for body tissues. Certain glands use it to produce corticosteroids and hormones, including testosterone and estrogen. The liver uses it to help make the bile acids you need in order to digest and absorb fats. Cholesterol is also an important precursor to vitamin D. Cholesterol gets is bad name because high blood levels of LDL cholesterol are linked to heart attacks, strokes and other cardiovascular diseases.