Triglycerides are a type of fat found in your blood and a major source of energy for your body. Most triglycerides are stored in the fat tissue, however, some always circulate in the blood to provide energy for your muscles to work. Having high levels of triglycerides is linked to an increased risk of heart disease.  

Triglycerides are obtained from the food you eat. Butters, oils, and other fatty foods are the major sources of triglycerides. In addition to this, the extra calories that you consume that is more than you need for your energy needs is converted into triglycerides, mainly by your liver. The body stores them in fat cells to be used later. In between meals, hormones release them as fatty acids to provide energy to the body. 

High levels of triglycerides, especially combined with high levels of LDL cholesterol and low levels of HDL cholesterol, are known to cause atherosclerosis. This is when the walls of your arteries get harder and thicker due to a plaque that builds up on the inner side. The arteries - blood vessels that carry blood with oxygen and nutrients around your body – thus become narrower, and can lead to stroke, heart attack, or heart disease. Very high triglyceride levels are associated with pancreas inflammation and metabolic syndrome. Elevated levels can also be a sign of hypothyroidism or an early sign of type 2 diabetes. Some drugs like diuretics, steroids, estrogen, and progestin or HIV medications can also cause your triglyceride levels to rise. 

As much as triglycerides cause problems when their levels are high, not having enough of them can be connected to malabsorption, which means the nutrients from food are not being properly absorbed in the small intestine. Hyperthyroidism, long-term fasting, and a very low-fat diet also cause triglyceride levels to drop.