Triglycerides are a major energy source for cells and serve as the primary way of lipid storage. Increased triglyceride levels are seen in multiple diseases affecting lipid metabolism, such as diabetes mellitus, hypothyroidism, Cushing’s disease and nephrotic syndrome, as well as obesity and eating before blood sampling. Triglycerides are transported from the gut to tissues in chylomicrons, whereas VLDL particles carry triglycerides from the liver into tissues. HDL and LDL also contain triglycerides, but their major role is in cholesterol transport. Lipoproteins are heat-sensitive and the measured concentration of triglycerides falls after one day of sample storage at room temperature.