What are triglycerides and how do they affect risk? 

Triglycerides are the most common type of fat found in your blood, serving as a primary source of energy for the body. While they are essential for health, having high levels a condition known as hypertriglyceridemia can significantly increase your risk of heart disease, stroke, and, in severe cases, acute pancreatitis. In the UK, a healthy non-fasting triglyceride level is generally considered to be below 2.3 mmol/L. 

When you consume calories, your body converts any that are not needed immediately into triglycerides, which are stored in your fat cells. Hormones later release these fats for energy between meals. However, if you regularly consume more calories than you burn, particularly from carbohydrates and fats, your levels can become chronically elevated. This condition often occurs alongside low levels of High-Density Lipoprotein (HDL) cholesterol, creating a combined risk factor for cardiovascular complications. 

What We will cover in this Article 

• The biological definition of triglycerides and how the body uses them. 

• How elevated levels contribute to the narrowing of the arteries. 

• An overview of the UK healthy reference ranges for fasting and non-fasting tests. 

• The specific lifestyle factors and medical conditions that trigger high levels. 

• The difference between triglycerides and cholesterol in terms of heart risk. 

• Evidence-based management strategies including diet and NICE-recommended medications. 

An Overview of Triglycerides and Their Role in the Bloodstream 

Triglycerides are lipids composed of three fatty acids attached to a glycerol molecule. They are either absorbed from the food you eat or produced by the liver from excess sugars and alcohol. They circulate in the blood within particles called lipoproteins, specifically chylomicrons and Very Low-Density Lipoproteins (VLDL), to be delivered to tissues for energy or storage. 

According to the British Heart Foundation (2025), approximately 10 percent of people in the UK have raised triglycerides. While they are a vital energy source, the liver can produce an excess when it is overwhelmed by high-sugar foods or alcohol. Because they are transported in the blood, an overabundance can lead to the ‘thickening’ of the blood and contribute to the build-up of fatty deposits in the vascular system. 

How do triglycerides affect your heart risk? 

High triglycerides contribute to the hardening and thickening of the artery walls, a process called atherosclerosis. This happens because triglyceride-rich particles can interfere with the way ‘good’ cholesterol works, making it less effective at clearing fat from the body. This significantly increases the risk of coronary heart disease and stroke. 

The clinical risk is especially high when high triglycerides are paired with high LDL (bad) cholesterol. Furthermore, according to NICE Guideline [NG238] (2023), extremely high levels (above 10 mmol/L) pose an immediate risk of acute pancreatitis. This is a painful and potentially life-threatening inflammation of the pancreas that requires urgent medical intervention. Clinical data suggests that for every 1 mmol/L increase in triglycerides, the risk of cardiovascular events rises, even if cholesterol levels appear normal. 

Causes and triggers of high triglycerides 

Several lifestyle factors and medical conditions can trigger a rise in triglyceride levels. Diet is the most common influence, particularly the consumption of refined sugars and alcohol, which the liver quickly converts into fat. 

The NHS identifies these primary triggers: 

• Dietary habits: High intake of saturated fats and ‘simple’ sugars like sweets and white bread. 

• Alcohol consumption: Even small amounts can significantly spike levels in sensitive individuals. 

• Health conditions: Type 2 diabetes, obesity, underactive thyroid, and kidney disease. 

• Medications: Certain drugs, including beta-blockers and some diuretics, can raise levels as a side effect. 

• Physical inactivity: A sedentary lifestyle prevents the body from effectively burning these fats for energy. 

Differentiation: Triglycerides vs. Cholesterol 

While both are lipids that circulate in the blood, they serve different purposes. Triglycerides store unused calories and provide your body with energy, while cholesterol is used to build cells and certain hormones. Because they travel together in lipoproteins, they are often measured together in a ‘lipid profile’ test. 

Feature	Triglycerides	Cholesterol
Primary Function	Energy storage and fuel.	Building cell membranes and hormones.
Main Source	Sugars, alcohol, and dietary fats.	Produced by the liver and found in animal fats.
Storage Site	Fat (adipose) cells.	Found in all cells of the body.
High Level Risk	Pancreatitis and atherosclerosis.	Atherosclerosis and heart attack.

To Summarise 

Triglycerides are a crucial energy source that can become a health risk when levels exceed the body’s requirements. In the UK, maintaining a non-fasting level below 2.3 mmol/L is advised to protect against cardiovascular disease. Management typically focuses on reducing alcohol and sugar intake, increasing aerobic exercise, and controlling underlying conditions like diabetes. For those with severely high levels, specialist referral and medication are necessary to prevent serious complications like pancreatitis. 

If you experience severe, sudden, or worsening symptoms, such as intense abdominal pain that radiates to your back, call 999 immediately. 

Authority Snapshot (E-E-A-T Block) 

This article was written by the MyPatientAdvice Medical Content Team and reviewed by Dr. Rebecca Fernandez to ensure clinical accuracy and adherence to 2026 UK medical standards. Dr. Fernandez is a UK-trained physician with an MBBS and extensive experience in cardiology, internal medicine, and emergency care. This guide provides evidence-based information on lipid management to support public health and informed patient choices.