What high triglycerides mean

Lab marker guide · Updated June 2026

Understanding lab results

What triglycerides measure

Triglycerides are the body's main way of storing and shipping energy. When you eat more calories than you burn — especially from sugar, refined carbs, and alcohol — your body converts the excess into triglycerides and stores them in fat cells, releasing them between meals for fuel.

A blood test measures the level circulating in your bloodstream. Because food sends triglycerides up sharply, the test is usually done fasting (8–12 hours without eating) so the result reflects your baseline rather than your last meal. A non-fasting sample can still be useful but tends to read higher.

The ranges that matter

Two units report the same result: mg/dL, common in the US, and mmol/L, standard in the UK and most of the world.

Read against the range and units printed on your report, and note whether the sample was taken fasting.

What high triglycerides mean

A raised triglyceride level usually signals that your body is taking in more fuel — particularly sugar, refined carbohydrates, and alcohol — than it's using. It frequently travels alongside excess weight around the middle, insulin resistance, and low HDL cholesterol: together these point to a metabolic pattern worth addressing.

The risk is twofold. Moderately high triglycerides are associated with greater cardiovascular risk, especially when paired with unfavourable cholesterol. Very high triglycerides — 500 mg/dL (5.6 mmol/L) and above — carry a more immediate concern: they can trigger acute pancreatitis, a painful and potentially serious inflammation of the pancreas, which is why very high readings need prompt medical attention.

Common causes

Triglycerides rise for a mix of lifestyle, metabolic, and medical reasons:

• Diet — diets heavy in added sugar, sugary drinks, white bread and other refined carbs are the classic driver, because the body turns surplus carbohydrate into triglycerides.
• Alcohol — even moderate intake can push triglycerides up noticeably; in sensitive people it's a major factor.
• Excess weight and inactivity — extra body fat and a sedentary routine both raise levels.
• Metabolic conditions — insulin resistance, type 2 diabetes, and an underactive thyroid (hypothyroidism) commonly elevate triglycerides; kidney and liver disease can too.
• Medications — some, including certain beta-blockers, steroids, and others, can raise them.
• Genetics — some people inherit a tendency to high triglycerides regardless of lifestyle.

How triglycerides fit with cholesterol

Triglycerides and cholesterol are both lipids carried in the blood, and they're reported together on the same lipid panel. They do different jobs — triglycerides store energy, cholesterol builds cell membranes and hormones — but they're read as a set:

• Triglycerides — circulating fat, strongly diet- and lifestyle-driven.
• LDL cholesterol — the "bad" cholesterol that drives plaque.
• HDL cholesterol — the "good" cholesterol; high triglycerides often go hand-in-hand with low HDL.

That clustering — high triglycerides plus low HDL — is part of why clinicians look at the whole panel rather than any single line. A triglyceride number makes the most sense read next to your LDL, HDL, and total cholesterol.

What to do about high triglycerides

The encouraging part: triglycerides are among the most responsive lab markers to lifestyle change, often improving within weeks.

• Cut added sugar and refined carbs — the single biggest lever for most people.
• Reduce or pause alcohol — frequently lowers levels quickly.
• Move more and lose excess weight — regular activity and even modest weight loss help.
• Eat oily fish or consider omega-3s — these can lower triglycerides; discuss supplements with your clinician.

If lifestyle changes aren't enough — or levels are very high — a doctor may add medication. Very high readings are treated more urgently because of the pancreatitis risk.

Why the trend matters

A single triglyceride reading is a moment in time, and it's especially sensitive to your last few days — a holiday weekend or a non-fasting sample can skew it. The direction across several tests is the real signal. Watching the number fall as you cut sugar and alcohol is powerful motivation, and plotting it next to your LDL, HDL, weight, and activity tells a far clearer story than scattered one-off numbers — see tracking lab results over time and how to read your blood test results.

When to talk to a doctor

Borderline-high or high triglycerides are worth raising with a clinician, who may repeat the test fasting, review your whole lipid panel, and look for underlying causes. A very high result (500 mg/dL / 5.6 mmol/L or above) deserves prompt attention. For more, see triglycerides in the blood test results library, the guide to lowering LDL cholesterol, and the rest of the Quanome blog.

Frequently asked questions

What is a normal triglyceride level?

A normal fasting triglyceride level is below 150 mg/dL (1.7 mmol/L). 150–199 mg/dL (1.7–2.2 mmol/L) is borderline-high, 200–499 mg/dL (2.3–5.6 mmol/L) is high, and 500 mg/dL (5.6 mmol/L) or above is very high. Triglycerides are usually measured after at least 8–12 hours of fasting.

What causes high triglycerides?

Common drivers are diets high in refined carbs, sugar and alcohol, excess weight, and inactivity. Triglycerides are also raised by insulin resistance and type 2 diabetes, an underactive thyroid, kidney disease, and certain medications. Some people have a genetic tendency toward high triglycerides.

How are triglycerides related to cholesterol?

Both are fats (lipids) carried in your blood and reported together on a lipid panel. Triglycerides store energy; cholesterol builds cells and hormones. High triglycerides often travel with low HDL ('good') cholesterol and are part of the same metabolic picture, which is why doctors read the whole panel rather than one number.

How do I lower high triglycerides?

Triglycerides respond strongly to lifestyle: cutting added sugar, refined carbs and alcohol, losing excess weight, and regular exercise can lower them substantially, often within weeks. Oily fish or omega-3s may help. Very high levels (500 mg/dL and above) raise pancreatitis risk and need prompt medical attention.