High Triglycerides on a Blood Test: What Does It Mean and What Next?

A high triglycerides result means your blood contained more of this type of fat than the laboratory's healthy range. Triglycerides store extra calories for energy. A raised level usually causes no symptoms, but over time it can add to the risk of heart disease and stroke, and very high levels raise the risk of pancreatitis.

One result is a starting point, not a diagnosis. Clinicians look at how high the value is, whether the sample was taken after fasting, your other lipid results, and your health history before deciding what comes next.

This guide is for adults reading an existing result. Children and teenagers use different ranges, so ask the child's clinician how to read their report.

A high triglyceride level itself rarely causes symptoms. The main danger with very high levels is acute pancreatitis, a sudden swelling of the pancreas. The NHS describes the main symptom as sudden, severe tummy pain that may feel knife-like and spread to the sides and back.

The NHS advises calling 999 or going to A&E (or your local emergency number) if you have sudden, severe tummy pain together with any of the following:

• pain spreading to your back
• bloating that persists or keeps coming back
• a fast heartbeat or difficulty breathing
• bluish or bruised-looking skin around the belly button, waist or upper outer thigh
• Sudden severe tummy pain that keeps returning, with a high temperature or feeling hot, cold or shivery, needs an urgent appointment the same day.

MedlinePlus and NHLBI give these adult categories in mg/dL: healthy is below 150, borderline high is 150 to 199, high is 200 to 499, and very high is 500 or more. Many countries, including the UK and Australia, report triglycerides in mmol/L instead, so check the units on your report.

Reference ranges and cut-offs differ between laboratories and guidelines. Always compare your value with the range printed on your own report and ask your clinician which category applies to you.

Triglycerides can change a lot after a meal, and even fasting levels vary from day to day. Lab Tests Online UK, run by the Association for Laboratory Medicine, says fasting is not routinely required, because non-fasting readings are now considered just as useful for most purposes.

Other services still ask for a fast before a lipid test. MedlinePlus mentions a fast of 9 to 12 hours, and Cleveland Clinic suggests 8 to 12 hours for the most accurate reading. Follow the instructions you were given for your test.

If your sample was non-fasting and the result is borderline or high, a clinician may suggest repeating it after fasting. Note on the form whether you had eaten so the result is read in context.

Several factors often act together. NHLBI, MedlinePlus and Cleveland Clinic list the following:

• Alcohol: drinking too much alcohol can raise triglycerides, and NHLBI notes that very high levels may call for stopping alcohol entirely.
• Diabetes: poorly controlled blood glucose can make triglycerides very high.
• Diet and activity: diets high in sugar, fat and refined carbohydrates, little exercise, and overweight or obesity.
• Other conditions: kidney disease, liver disease and thyroid disease, especially an underactive thyroid.
• Medicines: some diuretics (water pills), some breast cancer and HIV treatments, and others such as corticosteroids and beta-blockers named by Cleveland Clinic.
• Inherited conditions: some families have lipid disorders that stop the body breaking down fats properly.

NHLBI states that above 500 mg/dL the risk of acute pancreatitis rises. Lab Tests Online UK states that very high levels, at least 10 to 15 mmol/L, indicate a risk of pancreatitis and that lowering them is important. NHLBI adds that levels above 1,500 mg/dL can be linked to a condition called multifactorial chylomicronemia syndrome.

For people with very high levels, or pancreatitis without an obvious cause, NHLBI says genetic testing may be considered, especially when a close relative has had very high levels or pancreatitis. A very high result usually means your clinician will want to act sooner rather than simply repeat the test months later.

Next steps depend on the level and your overall risk. NHLBI lists lifestyle changes such as heart-healthy eating, regular physical activity, aiming for a healthy weight, limiting alcohol, stopping smoking and getting enough sleep. Some people also need medicine. Your clinician may check blood glucose, kidney, liver and thyroid tests to look for a cause, and may suggest an apolipoprotein B (ApoB) test.

Do not stop or change a prescribed medicine because you think it may be raising your triglycerides. Talk to the prescriber first. NHLBI also notes that over-the-counter omega-3 supplements are not FDA-approved to treat high triglycerides.

Bring your report, earlier results if you have them, a list of medicines and supplements, and an honest note of how much alcohol you usually drink.

• Was my sample fasting or non-fasting, and does that change how you read it?
• Which category is my level in, using this lab's range and units?
• Could alcohol, diabetes, thyroid, kidney or liver problems, or any of my medicines be playing a part?
• Is my level high enough to raise pancreatitis risk, and what symptoms should make me seek urgent care?
• How do my HDL, LDL and other results change my overall heart risk?
• When should the test be repeated, and what result would change the plan?

On SameCase, patients and verified doctors share de-identified cases. Reading how other people with high triglycerides described their results, fasting status, alcohol use and follow-up plans can help you notice questions you had not thought of before your appointment.

Other people's cases cannot tell you what your own result means or what treatment you need. Use them to prepare questions, and let your own clinician interpret your result.