Overview
High cholesterol (hypercholesterolaemia) means there is too much cholesterol in the blood, particularly low-density lipoprotein (LDL) cholesterol. Excess LDL deposits in artery walls, forming plaques that narrow and harden the arteries, increasing the risk of heart attack and stroke. It causes no symptoms until a cardiovascular event occurs.
How common is it?
Around 40% of adults in England have total cholesterol above 5 mmol/L. Familial hypercholesterolaemia, a genetic form, affects 1 in 250 people and causes markedly elevated LDL from birth.
Causes and risk factors
Cholesterol levels are determined by genetics, diet, and metabolic factors. The liver produces most of the body's cholesterol; the rest comes from diet.
Common risk factors
- Saturated and trans fat intake (raises LDL)
- Family history of high cholesterol or early cardiovascular disease
- Familial hypercholesterolaemia (genetic)
- Obesity and metabolic syndrome
- Physical inactivity (lowers HDL)
- Type 2 diabetes
- Hypothyroidism
- Chronic kidney disease
- Medications: thiazides, beta-blockers, corticosteroids
Symptoms
- None — high cholesterol is entirely asymptomatic until complications develop
- Familial hypercholesterolaemia may produce xanthelasma (fatty deposits around eyelids), tendon xanthomata, or corneal arcus
When to see a doctor
Cholesterol testing is recommended for all adults from age 40, and earlier if there is a family history of high cholesterol or early heart disease. Testing is part of the NHS Health Check offered to adults aged 40 to 74.
Diagnosis
Fasting or non-fasting lipid profile: total cholesterol, LDL, HDL, non-HDL, and triglycerides. QRISK3 score calculates 10-year cardiovascular risk combining cholesterol with other factors.
Treatments
Statins
Atorvastatin, rosuvastatin, and simvastatin are the mainstay of treatment. High-intensity statins (atorvastatin 80mg) reduce LDL by 50% or more. Side effects (myalgia) are real but less common than perceived.
Dietary modification
Replacing saturated fat with unsaturated fat, increasing soluble fibre (oats, pulses), and plant sterols/stanols reduce LDL by up to 15 to 20%.
Ezetimibe
Blocks cholesterol absorption in the intestine. Used in addition to statins when target is not reached, or alone in statin intolerance. Reduces LDL by a further 15 to 20%.
PCSK9 inhibitors
Injectable monoclonal antibodies (evolocumab, alirocumab) reduce LDL by up to 60%. Used for familial hypercholesterolaemia and very high-risk patients not reaching targets on maximal oral therapy.
Self-care and lifestyle
- Replace butter and lard with olive oil and rapeseed oil
- Eat oily fish twice a week (omega-3 fatty acids raise HDL and reduce triglycerides)
- Increase soluble fibre: oats, barley, lentils, apples, and citrus
- Exercise regularly (150 minutes moderate aerobic activity weekly)
- Avoid smoking (raises LDL and reduces HDL)
Prevention
A diet low in saturated fat and high in fibre, combined with regular exercise, is the cornerstone of cholesterol prevention. Genetic forms require early pharmacological treatment regardless of lifestyle.