Lipids, such as cholesterol, triglycerides, and fatty acids, are fat and substances like fat used as a source of fuel by the body. Lipid levels can be an important measure of health; for example, a person who has high cholesterol has an increased risk of heart disease and stroke.
Lipids are found in the bloodstream or stored in tissues. They are an important part of cell structure and other biological functions in the body.
WebMD Medical Reference from Healthwise