The best way to measure cholesterol is with a blood test called a lipid panel or lipid profile. You will need to fast (not eat) for 9 to 12 hours before your lipid panel. The test will determine the amounts of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in your blood, measured in milligrams per deciliter of blood (mg/dL). In adults more than 40 yrs of age cholesterol levels must be checked once in every 6 months.