Cholesterol, despite its negative reputation, is a vital fat in the body with essential roles like building cell membranes and producing important hormones such as testosterone and oestradiol. The liver produces cholesterol, and it also comes from the food we consume. Total cholesterol consists of HDL (high-density lipoprotein), which is beneficial for heart health, and LDL (low-density lipoprotein), which, when elevated, can contribute to cardiovascular issues. Just looking at the total cholesterol number doesn't provide a complete picture of heart disease risk. High levels of HDL cholesterol might elevate total cholesterol but can actually be protective against heart disease. Conversely, having a normal total cholesterol level doesn't necessarily mean good heart health if the protective HDL cholesterol levels are low. The critical factors are the levels of HDL and LDL cholesterol and the proportion of protective HDL in your total cholesterol. The detailed breakdown of these components is provided in the rest of your cholesterol profile.

LDL cholesterol, also known as low-density lipoprotein, is a combination of lipids and proteins that carries cholesterol, triglycerides, and other fats to different tissues in the body. Excessive levels of LDL cholesterol, often referred to as 'bad cholesterol,' may result in the buildup of fatty deposits within artery walls, potentially contributing to atherosclerosis and heart disease.

Your total cholesterol comprises two main components: HDL (considered good) and LDL (considered bad). Besides LDL, there are other harmful cholesterol types in your blood, including VLDL (very low-density lipoproteins) and other lipoproteins believed to be even more detrimental than LDL cholesterol. Non-HDL cholesterol is calculated by subtracting your HDL cholesterol value from your total cholesterol. This measurement encompasses all non-protective and potentially harmful cholesterol in your blood, not just LDL. Consequently, non-HDL cholesterol is considered a more accurate indicator of cardiovascular risk than total cholesterol and LDL cholesterol alone. The recommended level of non-HDL cholesterol is below 4 mmol/L.

HDL cholesterol, or high-density lipoprotein, is a body molecule that eliminates cholesterol from the bloodstream and carries it to the liver for breakdown and removal through bile. HDL cholesterol is widely recognized as 'good cholesterol.'

The cholesterol/HDL ratio is calculated by dividing your total cholesterol value by your HDL cholesterol level. It is used as a measure of cardiovascular risk because it gives a good insight into the proportion of your total cholesterol which is good (i.e. high-density lipoprotein HDL). Heart disease risk tools (such as QRisk) use the cholesterol/HDL ratio to calculate your risk of having a heart attack

Triglycerides, a form of fat or lipid, travel through the bloodstream. When you consume excess calories, whether from fats or carbohydrates, your body converts them into triglycerides. These triglycerides are then moved to cells for storage as fat and can be released when the body needs energy.