Hyperlipidemia, better known as high cholesterol, is elevated level of lipids (fats) like cholesterol and triglycerides in the blood. You do need some cholesterol in your blood for your cells to function, but too much cholesterol can cause your arteries to harden and narrow. This leads to decreased blood flow around the body. The condition can be genetic but is usually acquired, meaning you can prevent high cholesterol with diet and exercise.