High triglyceride causes include a number of factors, some of which are controllable. A high triglyceride count is usually caused by obesity, poorly controlled diabetes, an underactive thyroid, kidney disease, unhealthy diet (eating more calories than are burned), and drinking a lot of alcohol.ne needs some triglycerides for good health, but high triglycerides can increase the risk of heart disease, diabetes and stroke. It may also be a sign of metabolic syndrome, which is the combination of high blood pressure, high blood sugar, too much fat around the waist, and high triglycerides.