High blood levels of cholesterol or triglycerides is known as hyperlipidemia. Both dietary and genetic factors contribute to high levels. Although cholesterol and lipids (fats) are needed for normal body metabolism, the typical American diet contains excessive amounts of these products.

There are many dietary sources of fat and cholesterol. Animal products are the sole source of cholesterol, although many other foods contain fat.
Animal products high in cholesterol and saturated fat include red meats, organ meats, high fat dairy products, sausages, bacon, etc. Certain vegetable products are high in fat, but they do not contain cholesterol.
Peanuts, avocados, and cooking oils are examples. In general, saturated fats, or those fats that are solid at room temperature, are considered more of a problem than mono or polyunsaturated fats. Oils such as olive oil and fish oil may actually help a high cholesterol condition, although they still contribute calories to the diet.

Hyperlipidemia can contribute to blood vessel blockages that may lead to heart attack, stroke, blindness, kidney failure or limb amputation.
Hyperlipidemia in combination with high blood pressure, smoking, or diabetes is even more dangerous.

Treatment of high cholesterol initially involves lifestyle modification.
Dietary restriction of fat and cholesterol is an important step. Regular exercise helps to decrease weight, which may help to lower high lipid levels. Furthermore, regular exercise helps to raise the level of HDL, or good cholesterol. This exerts a protective effect. If diet and exercise alone do not control the levels, medications are added to bring the condition under control.