The American Heart Association recommends cholesterol testing every 4 to 6 years for healthy people older than 20 as a method of predicting the likelihood of having a stroke or heart attack. Higher-than-normal levels of cholesterol in the blood may indicate the need for changes in diet and exercise habits, as well as medication prescribed by your doctor. Cholesterol tests may be done by finger stick in a public health setting or by testing a blood sample taken from a vein. To ensure the accuracy of the results, follow your doctor's instructions about whether to fast before the test.
Follow your doctor's instructions about fasting, as medical opinions vary. Eating before a cholesterol screening test will probably not alter the results, according to Paul Durrington, M.D., in his 2007 textbook, "Hyperlipidaemia 3Ed: Diagnosis and Management." If your doctor orders a lipid panel that measures triglycerides, cholesterol and other substances from a single blood sample, she may advise withholding food, medications and beverages other than water for 9 to 12 hours. However, some research, such as a 2008 study by the American Heart Association, has indicated that non-fasting lipid profiles may provide accurate results as well, so follow your doctor's instructions.