Triglycerides: Normal Range, High & Low Causes
What Triglycerides measures
Triglycerides store energy from the food you eat. High levels, especially with low HDL, raise the risk of heart disease, and very high levels can cause pancreatitis.
Triglycerides reference ranges
| Category | Conventional units | SI units |
|---|---|---|
| Normal | Below 150 mg/dL | Below 1.7 mmol/L |
| Borderline high | 150 – 199 mg/dL | 1.7 – 2.2 mmol/L |
| High | 200 – 499 mg/dL | 2.3 – 5.6 mmol/L |
| Very high | 500 mg/dL or above | 5.7 mmol/L or above |
Triglycerides rise after meals, so a fasting sample gives the most comparable number.
Need to convert units? Use the mg/dL ↔ mmol/L converter.
Common causes of a high result
- Excess calories, sugar and refined carbohydrates
- Alcohol
- Obesity, diabetes and insulin resistance
- Underactive thyroid and kidney disease
- Some medicines, including certain steroids, estrogen and diuretics
- Inherited lipid disorders
Common causes of a low result
- Very low-fat diets or malnutrition
- Overactive thyroid
- Malabsorption
- Some lipid-lowering medicines
How to prepare for the test
Many labs ask for 9–12 hours of fasting. Avoid alcohol for 24 hours before the test.
How often to retest
As advised. After lifestyle changes or new treatment, clinicians often recheck in 6 to 12 weeks.
Track Triglycerides over time
Upload your reports and Labgist plots every Triglycerides result on one timeline, converts units and shows what changed.
Get the appFrequently asked questions
What is a normal triglyceride level?
Below 150 mg/dL (1.7 mmol/L) in a fasting sample.
What lowers triglycerides fastest?
Cutting alcohol and sugary drinks, reducing refined carbohydrates, losing excess weight and exercising usually have the biggest effect. Your clinician may add medicine for very high levels.
Why does fasting matter for triglycerides?
Triglycerides climb after eating and can vary a lot within a day, so a fasting sample is the most reliable for comparing results over time.
Related tests
Sources
This page is general education and was last updated 2026-10-30. It is not a substitute for medical advice. See our editorial approach.