High Cholesterol (Hyperlipidaemia)
Understanding raised blood lipids, cardiovascular risk and how to lower cholesterol safely
High cholesterol — known medically as hyperlipidaemia — is one of the most common and most significant cardiovascular risk factors in the UK. Around 60% of adults in England have a total cholesterol level above the recommended target. Despite being largely symptomless, raised cholesterol silently damages blood vessels and dramatically increases the risk of heart attack and stroke. The good news is that it is highly treatable.
What is cholesterol and why does it matter?
Cholesterol is a fatty substance produced by the liver and found in some foods. It travels around the bloodstream in packages called lipoproteins. Low-density lipoprotein (LDL) cholesterol — often called 'bad' cholesterol — deposits fat in artery walls, causing atherosclerosis (hardening and narrowing of arteries). High-density lipoprotein (HDL) cholesterol — 'good' cholesterol — helps remove LDL from the bloodstream. Triglycerides are another type of blood fat that also contribute to cardiovascular risk when elevated. A fasting lipid profile measures all of these.
How is cardiovascular risk assessed?
NICE (NG238, 2023) recommends using the QRISK3 calculator to estimate a person's 10-year risk of a cardiovascular event. QRISK3 takes into account age, sex, ethnicity, blood pressure, cholesterol ratio, smoking status, body mass index, family history, diabetes, kidney disease, and a range of other factors. A QRISK3 score of 10% or above (i.e., a 10% or greater chance of heart attack or stroke in the next 10 years) generally indicates that a statin is recommended. All adults with established cardiovascular disease (heart attack, stroke, angina, peripheral arterial disease) should be offered a high-intensity statin regardless of their QRISK3 score.
How is high cholesterol treated?
High-intensity statins — most commonly atorvastatin 80 mg — are the first-line treatment for primary prevention (QRISK3 ≥10%) and mandatory for all patients with established cardiovascular disease (secondary prevention). Statins work by inhibiting an enzyme in the liver called HMG-CoA reductase, reducing LDL cholesterol by 40% or more. If LDL targets are not achieved with a statin alone, ezetimibe may be added — it reduces LDL by a further 15–20% by blocking cholesterol absorption from the gut. For very high-risk patients who cannot reach LDL targets with statin and ezetimibe, injectable PCSK9 inhibitors (evolocumab or alirocumab) are available under specific NICE criteria.
Lifestyle and what you can do
Lifestyle changes can meaningfully lower cholesterol and should accompany medication. Reducing saturated fat (found in butter, full-fat dairy, fatty meats and pastries) and replacing it with unsaturated fats (olive oil, nuts, oily fish) reduces LDL. Increasing dietary fibre — particularly soluble fibre from oats, pulses and fruit — further lowers cholesterol. Regular aerobic exercise raises HDL cholesterol. Stopping smoking and limiting alcohol are also important. Plant stanols and sterols (available in fortified foods) can reduce LDL by around 10–15% when used regularly. All information in this article has been prepared following careful evaluation of current NICE guidance on cardiovascular risk and lipid modification (NICE NG238, 2023).