Triglycerides test explained (TG)

Triglycerides are the most common form of fat in the body: calories from food that are not used straight away are turned into triglycerides and stored in fat cells, and between meals hormones release them for energy. In the blood, triglycerides are carried by lipoproteins, which is why they are measured together with cholesterol in a lipid panel. Raised triglycerides contribute to atherosclerosis and increase the likelihood of a heart attack and stroke, while very high levels (above 5.65 mmol/l) can cause inflammation of the pancreas. The result is strongly affected by the last meal and by alcohol, so the test requires 8-12 hours without food. Triglycerides are closely linked to carbohydrate metabolism: they are often raised in obesity, prediabetes and uncontrolled diabetes.

• As part of a lipid panel — a preventive assessment of cardiovascular risk
• With risk factors present: excess weight, diabetes, raised blood pressure, heart disease in the family, smoking
• When inflammation of the pancreas is suspected — very high triglycerides can be its cause
• To follow the effect of lifestyle changes or of treatment

High triglycerides are most often linked to a diet high in carbohydrates and low in protein, excess weight, alcohol and uncontrolled diabetes. Other causes are liver disease (cirrhosis), thyroid disorders, kidney disease, some medicines and inherited disorders of lipid metabolism. Very high triglycerides can cause inflammation of the pancreas.

• A diet high in carbohydrates and low in protein
• Excess weight and alcohol
• Uncontrolled diabetes
• Liver disease — cirrhosis, liver damage
• Thyroid disorders
• Kidney disease
• Some medicines
• Inherited disorders of lipid metabolism

What to discuss with a doctor:

• Whether the test really was done after 8-12 hours without food and without alcohol
• Glucose and HbA1c — triglycerides often rise together with disorders of sugar metabolism
• Thyroid, liver and kidney markers, if the cause is not clear
• Overall heart risk together with cholesterol, blood pressure and other factors

Low triglycerides are usually not a concern. A very low value can be linked to a very low amount of fat in the diet, an overactive thyroid, problems absorbing fat, or inadequate nutrition.

• Very little fat in the diet
• An overactive thyroid
• Problems absorbing fat (malabsorption)
• Inadequate nutrition

• Whether there are other signs — weight loss, diarrhoea
• Thyroid markers, if the value is unexpectedly low

Triglycerides 1.7-2.2 mmol/l (borderline): in the MedlinePlus classification, the borderline high category covers results of 150-199 mg/dl (1.69-2.25 mmol/l) — no longer normal, but not yet clearly high triglycerides. It is most often linked to a diet high in carbohydrates, excess weight and alcohol, and such a value often appears because of the last meal, alcohol before the test or temporary changes in diet, so one result is rarely treated as final. Doctors usually suggest repeating the test after proper preparation — 8-12 hours without food and no alcohol for a few days before — because these factors can temporarily raise triglycerides even in a healthy person. The whole lipid panel (total cholesterol, LDL, HDL) and glucose are assessed at the same time, since a borderline triglyceride level often coincides with mild changes in carbohydrate metabolism or weight. One borderline result is not in itself a diagnosis and usually does not call for urgent treatment; but if it repeats several times or comes together with other risk factors — excess weight, raised blood pressure or family history — a doctor may assess overall cardiovascular risk in a wider context.

Triglycerides 2.3-5.6 mmol/l (high): in the MedlinePlus classification, 200-499 mg/dl (2.26-5.64 mmol/l) is considered high triglycerides. This is a level clearly above normal, which increases the risk of cardiovascular disease and stroke. The causes can vary — from diet and excess weight to uncontrolled diabetes, thyroid or kidney disorders, some medicines, or inherited features of lipid metabolism. In this case a doctor usually assesses not only triglycerides but the whole lipid panel (total cholesterol, LDL, HDL), glucose and HbA1c, because high triglycerides are often linked to disorders of sugar metabolism or to metabolic syndrome. It is important to check whether the test was done properly while fasting, since the last meal and alcohol can artificially raise the result. One result in this band does not by itself establish a diagnosis — the cause and the next steps are assessed by a doctor, taking into account overall health, other tests and risk factors such as family history or blood pressure.

Triglycerides above 5.6 mmol/l (very high): in the MedlinePlus classification, 500 mg/dl and above (5.65 mmol/l and above) is considered very high triglycerides. This is the highest band of the classification and is associated with an increased risk of acute inflammation of the pancreas (pancreatitis), especially when the value is well above the limit. A doctor usually assesses such a result faster than the other bands — it is important to check whether the test was done properly after 8-12 hours without food and without alcohol, because these factors can artificially raise the result. Glucose, HbA1c, liver and thyroid markers are checked at the same time, as well as the medicines being taken, because very high triglycerides are often linked to uncontrolled diabetes, liver disease or inherited disorders of lipid metabolism. One very high result is not in itself a diagnosis, but because of the possible risk of inflammation of the pancreas, MedlinePlus recommends discussing it with a doctor without delay rather than waiting for the next scheduled visit. The test is usually repeated to see whether the value comes down, and it is worth clarifying with a doctor when to seek help urgently — for example if abdominal pain or other symptoms appear.

Paying privately at a Lithuanian laboratory such as Medicina practica, a triglycerides test costs from €5 (September 2026 pricing). Prices depend on the laboratory and can change, and it is worth checking reimbursement conditions with the laboratory and with your doctor.