Triglycerides
Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.
A triglycerides test measures the level of triglycerides, a type of fat, in a blood sample, usually taken from a vein and often as part of a lipid profile. It is used to assess the risk of cardiovascular disease and to help detect or monitor conditions such as high cholesterol, metabolic syndrome, and pancreatitis risk associated with very high triglyceride levels.
Why get tested?
As part of a full lipid profile to assess the risk of developing cardiovascular disease, or to look for an underlying cause for a condition called pancreatitis
When to get tested?
As part of a lipid profile during a medical examination, after a diagnosis of pancreatitis, or if you are being treated for high triglycerides
Sample required?
A blood sample taken from a vein in the arm
Test preparation needed?
None. Fasting is not routinely required when checking triglyceride concentration (the guidance on this changed in 2014). However, there may be circumstances when fasting is still required, so follow your doctor’s advice.
Common questions
The most common reason for checking triglycerides is as part of a lipid profile to estimate risk of development of cardiovascular disease. Triglycerides are a form of lipid (fat), and are therefore included as part of a lipid profile. However, unlike cholesterol, which is very clearly an important cause of cardiovascular disease, the relationship between triglycerides and cardiovascular disease is less marked, but still important. Therefore, it is better to aim to keep your blood triglyceride concentrations low, particularly if you are at risk of cardiovascular disease for another reason.
Having high triglycerides can also lead to a serious medical condition called pancreatitis, which is inflammation of the pancreas gland. Therefore, if you get pancreatitis, triglyceride concentrations in the bloodstream should be checked to see if this is the cause. There are many other causes however.
A lipid profile, including triglycerides, is commonly tested by your GP when you reach the age of 40, as part of a routine cardiovascular health check. It will also be checked if you are already thought to be at risk of cardiovascular disease for another reason, such as having diabetes, high blood pressure, being a smoker, or being overweight.
Due to the link between high triglycerides and pancreatitis, triglyceride concentrations will be checked if you are diagnosed with this condition.
Having high triglycerides is thought to put you at higher risk of developing cardiovascular disease. This may also be because high triglycerides can be associated with an underlying condition, such as diabetes or obesity, which also increases cardiovascular risk.
If your triglyceride concentration is very high (e.g. at least 10–15 mmol/L), this indicates you are at risk of pancreatitis. In these circumstances, it is important to try and lower your triglyceride levels, which might involve either drugs or lifestyle changes, depending on the cause.
There are many factors which can cause high triglycerides. Examples include a high fat or high sugar diet, high intake of alcohol, obesity and diabetes. Lifestyle changes can therefore be very effective in reducing triglyceride levels. Drug treatments are also available if lifestyle changes are insufficient. There are also genetic factors which increase triglyceride levels. Raised triglyceride levels may also be secondary to pregnancy, kidney disease, liver disease, or an under active thyroid gland (hypothyroidism).
If you are diabetic and your blood glucose concentrations are out of control, triglyceride concentrations will be very high.
Triglyceride levels in the blood may change dramatically after a meal. Even fasting levels vary considerably from day to day. Because of the day-to-day variation, modest changes in fasting triglycerides measured on different days are not considered to be unusual or abnormal.
There are rare genetic conditions resulting in very high levels of triglyceride from birth resulting in pancreatitis (lipoprotein lipase deficiency or familial chylomicronaemia syndrome). Specialised treatment is now available for this condition, however, management is mostly based on very low fat diets.
Previously, fasting for 12 hours was recommended, as triglycerides increase after a meal for several hours. However, studies now show that readings after a meal are just as useful as fasting levels. There may be instances where your doctor recommends having the sample taken when fasting, so follow their advice.
Since triglycerides are circulating forms of fat, you might think that a high fat diet will raise triglycerides and a low fat diet will lower triglycerides. This is true, but carbohydrate also has a very important effect on triglycerides. Diets high in carbohydrates, especially sugar, lead to increases in triglycerides, as do diets rich in fats.
Yes. Exercise is especially helpful in lowering triglycerides and raising HDL (which tends to decrease when triglycerides increase). Even in the absence of weight loss, exercise will help you lower both LDL cholesterol and triglycerides, while raising HDL cholesterol.
While there are products available to monitor triglycerides at home, there is currently no clinical indication for which this is recommended.