What causes high triglyceride levels?

Many reasons: Genetic disorder , diabetes , hyperlipidemia and eating too many carbs and alcohol are some of the reasons.

Many causes: Triglycerides ( fat) can by elevated by many causes. Diet, including both fat and sugar intake can do this. Medications, other diseases such as diabetes, kidney disease, or liver disease can also cause high tg's. Alcohol, estrogen, are common causes and finally less common, but often more severe are genetic or inherited disorders of triglyceride metabolism.