Triglycerides are a type of fat in your blood that your body uses for energy. When a blood test measures your triglycerides, it’s checking how much of this stored fuel is circulating through your bloodstream, with levels below 150 mg/dL considered healthy for adults. Your results appear on a standard lipid panel, the same blood draw that checks your cholesterol.
What Triglycerides Actually Do
Every time you eat, your body converts calories it doesn’t need right away into triglycerides. These get packed into fat cells for storage. Between meals, hormones signal those fat cells to release triglycerides back into the bloodstream so your muscles and organs have fuel to keep running. It’s a straightforward system: eat more than you burn, and triglycerides accumulate. Burn what you eat, and levels stay low.
Triglycerides and cholesterol both show up on the same blood test, but they do very different jobs. Triglycerides are pure energy storage. Cholesterol is a building material your body uses to construct cell walls and make hormones. Both are lipids (fats that travel through your blood), but having too much of either creates different problems.
How to Read Your Results
The National Heart, Lung, and Blood Institute breaks adult triglyceride levels into four categories:
- Healthy: Below 150 mg/dL
- Borderline high: 150 to 199 mg/dL
- High: 200 to 499 mg/dL
- Very high: 500 mg/dL or above
For children and teens aged 10 to 19, the healthy threshold is lower, at 90 mg/dL. If your number lands in the borderline or high range, it’s worth paying attention to but not cause for alarm on its own. A single reading can be influenced by a recent meal, alcohol, or even a stressful week. Very high levels, above 500 mg/dL, carry more immediate health risks and typically require treatment.
Fasting Before the Test
You’ll usually be asked to fast for 9 to 12 hours before a triglyceride blood draw. That means no food or drinks other than water. The reason is simple: triglycerides spike after eating, sometimes dramatically. A meal two hours before the test could push your reading well above your true baseline. Your provider will tell you whether fasting is required, since some newer guidelines allow non-fasting panels for initial screening.
Why High Triglycerides Matter
Elevated triglycerides don’t directly clog your arteries the way you might assume. The fat molecules themselves don’t pile up inside artery walls. Instead, triglycerides travel through your blood inside particles called triglyceride-rich lipoproteins, and those particles carry cholesterol with them. When triglyceride levels are high, the concentration of cholesterol in these particles rises too. The particles break down in artery walls, get absorbed by immune cells, and fuel the inflammation that builds plaque over time. So a high triglyceride reading is really a signal that a dangerous form of cholesterol is elevated alongside it.
At extreme levels, a different risk takes over entirely. The chance of acute pancreatitis, a painful and potentially serious inflammation of the pancreas, increases progressively once triglycerides exceed 500 mg/dL. Above 1,000 mg/dL, the risk reaches roughly 5 percent. Above 2,000 mg/dL, it climbs to 10 to 20 percent. This is why the “very high” category gets treated more aggressively than the others.
Common Causes of High Triglycerides
The most frequent driver is simply consuming more calories than your body uses, especially from sugar, refined carbohydrates, and alcohol. Your liver converts excess sugar into triglycerides efficiently, which is why someone who drinks heavily or eats a lot of processed food can have sky-high levels even if their diet isn’t particularly fatty.
Other factors that raise triglycerides include carrying excess weight (particularly around the midsection), uncontrolled type 2 diabetes, an underactive thyroid, kidney disease, and certain medications like steroids and some blood pressure drugs. Genetics also play a role. Some people inherit a tendency to produce more triglycerides or clear them from the blood more slowly, leading to elevated levels even with a reasonable diet.
Lowering Triglycerides Through Lifestyle
Diet changes tend to produce the most noticeable results. Cutting back on added sugars, white bread, pasta, and sugary drinks reduces the raw material your liver uses to manufacture triglycerides. Limiting alcohol has a particularly strong effect because alcohol is converted to triglycerides almost directly. Replacing refined carbohydrates with fiber-rich foods, vegetables, and healthy fats (like those in nuts, olive oil, and fatty fish) shifts the balance.
Exercise helps through a different mechanism. Physical activity activates enzymes that break down triglycerides in your bloodstream. Research shows that a single session of sustained aerobic exercise can reduce triglycerides by 17 to 22 percent within 24 hours, with longer sessions producing even bigger drops (up to 33 percent). The effect is temporary, which is why consistency matters more than intensity. Regular moderate exercise, something like brisk walking or cycling most days, keeps those enzymes active and prevents triglycerides from accumulating.
Losing even a modest amount of weight amplifies both of these effects. Fat cells release fewer triglycerides when there are fewer of them, and the liver produces less when it isn’t processing a calorie surplus.
When Medication Is Needed
Lifestyle changes are the first approach for borderline and moderately high levels, but very high triglycerides (500 mg/dL and above) often require medication to bring levels down quickly enough to reduce the risk of pancreatitis.
The most commonly prescribed medications for triglyceride-specific lowering are fibrates, which reduce levels by 30 to 50 percent depending on how elevated they are to start. Statins, which are primarily cholesterol drugs, also lower triglycerides by 10 to 30 percent and are often already prescribed for people with cardiovascular risk. High-dose prescription omega-3 fatty acids (not the same as over-the-counter fish oil supplements) lower triglycerides by about 20 to 30 percent in the high range and by 30 percent or more when levels are very high. Niacin, a B vitamin given at therapeutic doses, can reduce triglycerides by 20 to 50 percent, though it’s used less frequently now due to side effects.
Your provider will choose a medication based on how high your levels are, whether you also have elevated cholesterol, and what other health conditions are in the picture. For most people in the borderline or high category, consistent lifestyle changes are enough to bring the number into the healthy range within a few months.