Medically reviewed by Dr Nabila Laskar, Consultant Cardiologist (GMC 7040901). High cholesterol means there is too much cholesterol in your blood, increasing the risk of fatty deposits building up in artery walls — raising the risk of heart attack and stroke. It causes no symptoms, which is why blood testing is the only way to detect it.
A full lipid panel measures several components. Total cholesterol gives an overall picture, but the breakdown matters more: LDL ("bad" cholesterol) contributes to arterial plaque; HDL ("good" cholesterol) helps remove it; triglycerides are another blood fat associated with cardiovascular risk; and Lp(a) — lipoprotein(a) — is an often-overlooked inherited risk marker that standard panels frequently miss. For a deeper explainer see /blog/understanding-cholesterol.
Causes include diet high in saturated fat, physical inactivity, excess weight, smoking, and alcohol. Genetics play a significant role — familial hypercholesterolaemia (FH) is an inherited condition causing very high LDL from birth regardless of lifestyle, affecting approximately 1 in 250 people in the UK. Secondary causes include underactive thyroid, diabetes, and kidney disease.
Excess LDL cholesterol deposits in artery walls over years, forming plaques that gradually narrow the vessel lumen. If a plaque ruptures, it triggers clot formation that can block the artery completely — causing a heart attack or stroke. This process is largely silent until a significant event occurs, which is why early detection matters.
Management depends on individual cardiovascular risk, not cholesterol number alone. Lifestyle changes — diet modification, regular aerobic exercise, weight management — are the foundation. Statins are the most commonly prescribed medication and are highly effective at lowering LDL. For those who cannot tolerate statins, or for very high-risk patients, newer agents including PCSK9 inhibitors offer an alternative. Treatment decisions are made in the context of your overall risk profile, family history, and existing conditions.
Total cholesterol above 7.5 mmol/L, or LDL above 5.0 mmol/L, is generally considered significantly elevated and warrants prompt assessment, particularly with other cardiovascular risk factors present.
Yes, in some cases — particularly where levels are moderately raised and lifestyle changes are meaningful. However, inherited high cholesterol (familial hypercholesterolaemia) almost always requires medication regardless of lifestyle.
Most people tolerate statins well. Muscle aches are the most common side effect, affecting a minority of users. For those who experience problems, alternative medications are available. The cardiovascular benefit of treatment in high-risk individuals significantly outweighs side effect risk.
Lipoprotein(a) is an inherited cholesterol-carrying particle not measured in routine lipid panels. High levels significantly increase cardiovascular risk independently of LDL. Testing is recommended for anyone with a personal or family history of early heart disease.