You may be familiar with high-density, or good cholesterol; low-density lipoproteins (LDL), or bad cholesterol; and their connections to heart health. But what about triglycerides? Often that word gets skimmed over when talking about cholesterol levels. Dr. Regis Fernandes, a Mayo Clinic cardiologist, says triglycerides provide the body with energy from food. High levels can indicate signs of other conditions, like diabetes or prediabetes, that can increase the risk of heart disease and stroke.