Triglycerides are a type of fat found in the blood and can be an indicator of Heart disease. High levels of this fat are caused by a variety of factors. These include: obesity, poorly controlled Diabetes, underactive thyroid, kidney disease, excessive alcohol consumption and regularly eating more calories than what is burned. Some medicines also raise triglyceride levels including Tamoxifen, steroids, beta-blockers, diuretics, estrogen and Birth Control pills. In some cases, high triglyceride levels can be hereditary. Normal triglyceride levels are under 150 mg/Dl.