What Do Rising or Falling Triglyceride Levels Mean?

Perhaps less well-known than their cousin cholesterol, triglycerides are a type of fat found in the blood. High or low triglyceride measures may be a sign of a problem — and a bit of background can help you talk it over with your doctor.

According to researchers at the Cleveland Clinic, cholesterol is both a product of your liver and of animal foods. It is not actually a fat, but rather a waxy, fatty-like substance. By contrast, triglycerides are primarily derived from food and are most definitely a fat.

Cholesterol is a necessary component of your cell walls and nerves, adds Cleveland Clinic, and it's also key to digestion and hormone production. Triglycerides, on the other hand, are essentially a rainy day supply of excess energy that gets stockpiled in fat cells whenever you take in more food than you need, notes the Mayo Clinic.

That's good news because if and when you find yourself running on empty, triglycerides will be there to step in and provide your body with the fuel it needs between meals. Still, as with cholesterol, when triglyceride levels go up too high or fall too low, it may indicate a health risk.

Read more: What's the Difference Between Triglycerides and Cholesterol?

Triglyceride levels are measures in milligrams per deciliter, or mg/dL. "Triglyceride levels below 150 mg/dL are considered normal," explains Gregg Fonarow, MD, director of the Ahmanson-UCLA Cardiomyopathy Center and co-director of the UCLA Preventative Cardiology Program.

But Mayo Clinic notes that, when levels rise to between 150 and 199, that's considered "borderline high." If they rise to the 200 to 499 level, that's deemed to be "high," whereas anything 500 and up is deemed "very high." And both Mayo Clinic and Cleveland Clinic caution that high triglyceride levels can ultimately raise your risk for heart disease.

These high levels can lead to a hardening or thickening of arterial walls. That boosts the risk for strokes and heart attacks. And high triglyceride levels can be a sign that other health issues may be present, such as Type 2 diabetes, thyroid problems or metabolic syndrome.

It's also the case that some drugs — including diuretics, estrogen, progestin, steroids, beta blockers and some HIV meds — may have the side effect of driving up triglyceride levels.

However, there are a wide range of interventions that can help bring triglyceride levels back down to healthy levels, according to Mayo Clinic. Those include lifestyle changes that prompt weight loss, such as exercising more and consuming fewer refined carbs, sugar and alcohol, as well as medications, like statins and niacin (also known as nicotinic acid).

As always, talk to your doctor before taking any over-the-counter supplement. Niacin can interact with other medications and cause significant side effects, says Mayo Clinic.

There's actually no threshold for when triglyceride levels would be characterized as too "low." And Dr. Fonarow stresses that, "in the absence of underlying disease, low triglycerides are generally not of concern."

However, he says, "very low levels of triglycerides can indicate the presence of malnutrition or chronic disease." Also, triglyceride levels that drop too steeply could be a sign of a number of health issues or recent diet changes, according to the Icahn School of Medicine at Mount Sinai.

One could be the presence of an overactive thyroid, a condition known as hyperthyroidism. That, the Icahn School notes, is when the thyroid gland produces excessive amounts of the thyroid hormone, giving rise to a wide range of unpleasant symptoms, including restlessness, nervousness, sleeplessness, difficulty concentrating and weight loss.

Another possible issue could be malabsorption syndrome — a condition when the small intestine fails to absorb fats as it should. The Icahn School notes that there are a number of illnesses that might cause this to occur, including celiac disease and Crohn's disease. Bacterial infection and radiation treatment could also be triggers.

Last, the Icahn School notes that excessively low triglyceride levels may reflect malnutrition. Prolonged adherence to an extremely low-fat diet could be the culprit, as could anorexia or other eating disorders.

As always, if you have any questions, ask your doctor to review your triglyceride levels and cholesterol levels with you to get a good picture of your overall health.

Read more: How Quickly Do Cholesterol or Triglyceride Levels Rise After a Fatty Meal?