What are blood lipids?

“Blood Lipids” is the term used for all the fatty substances found in the blood, including cholesterol and triglycerides.  Some people have too much cholesterol (fat) in their blood and this increases their chances of having a heart attack.

What is cholesterol?

Cholesterol is a fatty substance which is mainly made in the body when the liver breaks down saturated fats in food.  This cholesterol then passes into the blood.  

Cholesterol travels in the bloodstream in two forms:

  • ‘Low Density Lipoprotiens’ (LDLs) – this is often called ‘bad cholesterol’ as it helps to deliver cholesterol to the body through the bloodstream.  
  • ‘High Density Lipoproteins’ (HDLs) – this is often called ‘good cholesterol’ as it helps to take bad cholesterol out of the bloodstream from parts of the body.

What are triglycerides?
Triglycerides are another type of fat found in the blood which mainly come from food. After you eat, fats in your food are broken down in the liver into triglycerides.  The liver can also convert excess calories (e.g. from drinking too much alcohol, sugar drinks, or eating too much fatty foods or meat) into triglycerides. These fatty triglycerides are released into your blood and are then transported through your body and used as energy or stored as fat. 

Why are blood lipids a risk factor for Coronary Heart Disease?

Having high levels of fat in you blood can lead to fatty deposits in the blood vessels in the body, including the coronary arteries (the blood vessels which supply the heart muscle with blood).  This leads to the narrowing or hardening of the coronary arteries.  There is more information in the ‘what is coronary heart disease (CHD)’ section.

The goal is therefore to aim to have: 

  • low levels of total fat in your blood
  • low levels of LDL cholesterol
  • high levels of HDL cholesterol
  • low levels of triglycerides