Cholesterol Blood Test Kit

Total cholesterol measures the combined amount of all cholesterol types circulating in your blood—including HDL, LDL, and other lipoprotein fractions. Despite cholesterol's poor reputation, it's actually essential for life: your body uses it to build cell membranes, produce steroid hormones (including testosterone, oestrogen, and cortisol), synthesise vitamin D in the skin, and make bile acids for fat digestion. About 80% of your cholesterol is manufactured by your liver, with dietary cholesterol contributing a smaller proportion. Total cholesterol on its own has significant limitations for assessing cardiovascular risk—a high total cholesterol could be driven by high protective HDL (which is actually beneficial) or high harmful LDL (which is concerning). Similarly, a 'normal' total cholesterol can mask dangerously low HDL. This is why the complete lipid panel breakdown is far more informative than total cholesterol alone. Results outside the normal range may need a follow-up with your GP.

LDL (low-density lipoprotein) cholesterol is commonly called 'bad cholesterol' because elevated levels are strongly associated with atherosclerosis—the progressive build-up of fatty plaques inside artery walls that underlies most heart attacks and strokes. LDL particles carry cholesterol from the liver to tissues throughout the body. While this transport function is necessary, excess LDL particles can penetrate and become trapped in artery walls, where they trigger an inflammatory response and the formation of atherosclerotic plaques. Over time, these plaques narrow arteries and can rupture, causing blood clots that block blood flow. LDL cholesterol is the primary target for cardiovascular risk reduction in clinical guidelines—lowering LDL has been consistently shown to reduce heart attack and stroke risk. Targets vary depending on overall cardiovascular risk, but lower is generally better. Lifestyle factors that reduce LDL include reducing saturated fat intake, increasing soluble fibre, regular exercise, and maintaining healthy weight. Results outside the normal range may need a follow-up with your GP.

Non-HDL cholesterol is calculated by subtracting your protective HDL cholesterol from your total cholesterol. It represents all the potentially atherogenic (artery-clogging) cholesterol in your blood—not just LDL, but also VLDL, IDL, and lipoprotein remnant particles, all of which can contribute to plaque formation in arteries. Many cardiovascular experts now consider non-HDL cholesterol a better risk marker than LDL alone because it captures the full atherogenic burden. This is particularly important for people with elevated triglycerides, who often have significant cholesterol carried in VLDL particles that standard LDL testing doesn't fully capture. Non-HDL also has the practical advantage of remaining accurate regardless of whether you've fasted—it's not affected by recent food intake the way triglycerides are. The recommended target for non-HDL cholesterol is below 4.0 mmol/L for most people, with lower targets (below 2.5 mmol/L) recommended for those at higher cardiovascular risk. Results outside the normal range may need a follow-up with your GP.

HDL (high-density lipoprotein) cholesterol is often called 'good cholesterol' because it helps protect against cardiovascular disease. HDL particles perform a crucial function known as 'reverse cholesterol transport'—they travel through the bloodstream collecting excess cholesterol from tissues and artery walls and carrying it back to the liver, where it can be broken down and excreted in bile. This process helps prevent cholesterol from accumulating in artery walls and forming plaques. Higher HDL levels are associated with lower cardiovascular risk—HDL above 1.0 mmol/L in men and 1.2 mmol/L in women is generally considered desirable, with higher levels offering greater protection. Low HDL is an independent cardiovascular risk factor even when LDL is within normal limits. Factors that increase HDL include regular aerobic exercise (one of the most effective interventions), moderate alcohol consumption, weight loss if overweight, and not smoking. Factors that decrease HDL include smoking, obesity, sedentary lifestyle, type 2 diabetes, and very high carbohydrate diets (particularly refined carbohydrates). Results outside the normal range may need a follow-up with your GP.

The total cholesterol to HDL ratio is calculated by dividing your total cholesterol by your HDL cholesterol. This ratio is more informative than total cholesterol alone because it reflects the balance between all cholesterol and protective HDL—essentially capturing whether your cholesterol is predominantly the helpful or harmful type. A lower ratio is better, indicating that a higher proportion of your total cholesterol is the protective HDL type. A ratio below 4 is generally considered optimal for cardiovascular health; a ratio of 4-6 indicates moderate risk; above 6 suggests increased cardiovascular risk. This ratio is used in cardiovascular risk calculators such as QRISK (used in UK general practice) to estimate your 10-year risk of heart attack or stroke and to guide decisions about preventive treatments. Improving this ratio involves either lowering total cholesterol (through diet, lifestyle, or medication) or raising HDL (through exercise, weight loss, and not smoking)—ideally both. Results outside the normal range may need a follow-up with your GP.

Triglycerides are the main form of fat that circulates in your blood and the most common type of fat stored in your body. After eating, your body converts excess calories—whether from fats, carbohydrates, or protein—into triglycerides, which are packaged into lipoprotein particles (mainly VLDL) and transported to fat cells (adipocytes) for storage. Between meals, hormones trigger the release of triglycerides from fat stores to provide energy. Elevated fasting triglycerides indicate that your body is taking in more calories than it's burning, or that there's impaired clearance of triglyceride-rich particles from the blood. This is commonly associated with excessive calorie intake (particularly from refined carbohydrates, sugars, and alcohol), obesity, insulin resistance, metabolic syndrome, and type 2 diabetes. Very high triglycerides (above 10 mmol/L) can cause pancreatitis. Moderately elevated triglycerides are associated with increased cardiovascular risk, partly because they're linked to small, dense LDL particles (which are particularly atherogenic) and low HDL. Fasting triglycerides below 1.7 mmol/L are generally desirable. Triglycerides are the lipid marker most dramatically affected by recent food intake, which is why fasting for 8-12 hours is essential for accurate measurement. Results outside the normal range may need a follow-up with your GP.