High Cholesterol: Overview and Risk Factors

High cholesterol, or hyperlipidemia, refers to elevated levels of cholesterol in the blood, which tend to increase the risk for atherosclerosis, heart disease, stroke, and other serious conditions.

Common types of lipids include low density lipoprotein (also called LDL, or bad cholesterol), high density lipoproteins (HDL or good cholesterol), and triglycerides (fat in the bloodstream). High concentrations of total cholesterol and LDL cholesterol, low levels of HDL cholesterol, and/or high levels of triglycerides increase the risk for cardiovascular disease.

High cholesterol results from excess cholesterol production in the liver, excess intake of fats and cholesterol from the diet, and/or decreased removal of cholesterol from the body. In particular, intake of saturated fats, found in animal products, such as meat, most dairy products (milk, cream, cheese, or butter), and tropical oils (palm, palm kernel, and coconut), is known to increase cholesterol levels.

High cholesterol usually causes no symptoms. It is typically detected during routine blood testing. Occasionally, fatty deposits under the skin (xanthelasmas and xanthomas) can occur.

Risk Factors

Although high cholesterol is a frequent finding in all demographic groups that follow Western diets, it occurs somewhat more commonly in men. Additional risk factors include:

• Family history
• Diets high in total fat, saturated fat, and cholesterol (see Nutritional Considerations)
• Diabetes mellitus
• Chronic kidney disease: Kidney disease is associated with hypertriglyceridemia.
• Hypothyroidism
• Obesity: Excess weight is associated with increased total cholesterol, LDL, and triglycerides, as well as with decreased levels of HDL.
• Physical inactivity
• Alcoholism
• Steroid use
• Oral contraceptive pills
• Smoking: Cigarette smoking lowers HDL levels and is a risk factor for cardiovascular disease.