Triglycerides vs. Cholesterol: How Are They Different and How Are They the Same?

“Triglycerides” and “cholesterol” are two terms you’ve likely heard in relation to heart health. Your doctor may have ordered blood tests to measure the levels of these substances in your blood to determine your risk for cardiovascular disease. (The American Heart Association recommends that adults 20 and older have their cholesterol — high-density lipoprotein (HDL, or “good”), low-density lipoprotein (LDL, or “bad”, and total blood cholesterol— and triglycerides checked every four to six years, or more often if you have a higher risk for heart disease.) But just what are these numbers and how are they different?

While cholesterol and triglycerides are often mistakenly thought to be the same thing, they are different substances with different roles in the body. And just to add to the confusion, they have some similarities, too.

Cholesterol and triglycerides are both lipids, which are a type of fat found in the blood. “There are several categories to the lipid profile that doctors review: cholesterol, which encompasses both ‘good’ (HDL) and ‘bad’ (LDL, or non-HDL) cholesterol and triglycerides,” says Michael Wesley Milks, MD, a cardiologist and assistant professor of clinical medicine at The Ohio State University Wexner Medical Center in Columbus. Learning a bit more about triglycerides and cholesterol, including their differences and similarities, can help you understand the roles they play in your cardiovascular health.

What Are Triglycerides?

Triglycerides are found in some of the foods that you eat, such as oil and butter. They also come from consuming extra calories: When your body has more calories than it needs at any given time, it changes them into triglycerides, which are stored in fat cells. “Foods that lead to quickly available energy, particularly simple carbohydrate–rich foods, may result in higher triglyceride levels, especially in susceptible individuals, such as those with obesity or type 2 diabetes,” Dr. Milks says.

What Is Cholesterol?

Cholesterol is a waxy substance found in every cell in your body. Your body needs it to function, but your liver is able to produce all the cholesterol your body needs. If you get too much cholesterol from the foods you eat, such as meat, eggs, butter, and cheese, which are high in fat, this can become a problem. HDL absorbs cholesterol and carries it back to the liver, while LDL can lead to a buildup of cholesterol in your arteries.

Triglycerides and Cholesterol: The Similarities

Here are some things that triglycerides and cholesterol have in common.

On their own, triglycerides and cholesterol are not bad. When they are at healthy levels, they are both part of a well-functioning body. But both triglycerides and cholesterol tend to get a bad rap, because …

Too much of either isn’t good. When your body has too much LDL, it can increase your risk of heart attack and stroke. “Triglyceride elevations are known to associate with heart and vascular disease risk, although the relationship is not the same as with cholesterol,” Milks says.

Both can be checked with a blood test. Triglyceride and cholesterol levels can both be measured easily by your doctor using a blood test called a lipid profile. Your doctor may order the test as part of a routine exam or to monitor a condition, such as high cholesterol, high triglycerides, heart disease, or diabetes.

Both are treated in a similar way. In the case of both triglycerides and cholesterol, a healthy lifestyle is key. “Triglyceride levels are generally quite responsive to therapeutic lifestyle changes,” says Milks. “These include a healthy body weight, regular physical activity, a prudent diet, and no more than moderate alcohol consumption.” All of these habits can improve cholesterol levels, too.

But if you have a family history of high triglycerides or high cholesterol, lifestyle changes may not be enough to bring your lipid levels down into the healthy range. “Every person is a product of their genetic makeup and lifestyle exposures,” Milks says. If lifestyle changes aren’t sufficient, both conditions can be treated with medication.

Triglycerides and Cholesterol: The Differences

Although triglycerides and cholesterol share similarities, they are not the same. Here are some fundamental differences.

Triglycerides and cholesterol are produced differently. While the body can produce all the cholesterol it needs to function, this isn’t the case with triglycerides, which come from food or excess calories.

They serve different purposes in the body. While the primary function of triglycerides is to give your body energy and store unused calories for later, cholesterol helps your body build cells and make hormones, vitamin D, and bile to help break down the foods you eat.

When levels are too high, they can each harm your heart in different ways. The link between high cholesterol and heart disease is well established, and research on triglycerides is now bringing new insights. A study published in June 2020 in the journal BMJ Open found that in 50 year-old women, high levels of triglycerides — but not cholesterol — may be a risk factor for developing heart failure later. Growing evidence also ties high triglycerides to heart disease risk, regardless of cholesterol levels. “Both blood sugar and high triglycerides can be signs that the body isn’t using or storing energy appropriately,” Milks says.

Bottom line: Both triglycerides and cholesterol are important, and keeping both in check can help your heart stay at its healthiest.