Triglyceride levels in the blood are measured by a simple blood test. Often, triglycerides are measured as part of a lipoprotein panel (lipid panel) in which triglycerides, cholesterol, HDL (high density lipoprotein), and LDL (low density lipoprotein) are measured at the same time. Fasting for 8-12 hours before the test is required. Fat levels in the blood are affected by recent eating and digestion. Falsely elevated results may occur if the blood test is done just after eating.