Hyperlipidemias are a complex group of diseases that can be designated either primary or secondary, depending on their causes. Primary hyperlipidemias can result from a single inherited gene defect, or more commonly, are caused by a combination of genetic and environmental factors. Secondary hyperlipidemias are the result of a more generalised metabolic disorder, such as diabetes mellitus, excessive alcohol intake, hypothyroidism, or primary biliary cirrhosis. Therapeutic strategies for treating secondary hyperlipidemia caused by one of these disorders include dietary intervention plus a regimen of drugs used to treat the primary cause of the hyperlipidemia.