High Cholesterol: Levels, Causes, Diet and Treatment (UK Guide)

High cholesterol affects around 60% of adults in the UK, yet most people have no symptoms at all. Approximately 6 million people in the UK have high cholesterol that puts them at significant risk of heart attack and stroke, but are not receiving treatment. Understanding your cholesterol levels and what they mean is one of the most important steps you can take for your long-term heart health.

What Is Cholesterol?

Cholesterol is a fatty substance (lipid) found in every cell of your body. Your liver produces about 80% of the cholesterol your body needs; the rest comes from food. Cholesterol is carried in the bloodstream by lipoproteins:

  • LDL cholesterol (“bad” cholesterol) — carries cholesterol from the liver to cells; excess deposits in artery walls, causing atherosclerosis (hardening and narrowing of arteries)
  • HDL cholesterol (“good” cholesterol) — carries cholesterol back to the liver for removal; protective against cardiovascular disease
  • Non-HDL cholesterol — all cholesterol except HDL; NICE now recommends targeting non-HDL rather than LDL alone as it better captures cardiovascular risk
  • Triglycerides — another type of blood fat; elevated levels increase cardiovascular risk, especially when combined with low HDL

UK Cholesterol Targets

NICE guideline CG181 provides the following targets for people at risk of or with cardiovascular disease:

  • Total cholesterol: Below 5.0 mmol/L (general healthy adults)
  • LDL cholesterol: Below 3.0 mmol/L (general); below 2.0 mmol/L (if cardiovascular disease or high risk); below 1.8 mmol/L (very high risk)
  • Non-HDL cholesterol: Below 4.0 mmol/L (general); below 2.5 mmol/L (if cardiovascular disease)
  • HDL cholesterol: Above 1.0 mmol/L (men); above 1.2 mmol/L (women)
  • Triglycerides (fasting): Below 1.7 mmol/L

Causes of High Cholesterol

Lifestyle-Related (Most Common)

  • Diet high in saturated fat (red meat, full-fat dairy, butter, pastries, processed foods)
  • Physical inactivity
  • Overweight and obesity (particularly abdominal fat)
  • Smoking (lowers HDL cholesterol)
  • Excessive alcohol

Medical Conditions That Raise Cholesterol

Familial Hypercholesterolaemia (FH)

Familial hypercholesterolaemia (FH) is an inherited genetic condition causing very high LDL cholesterol from birth. It affects approximately 1 in 250 people in the UK — around 260,000 people — yet fewer than 15% have been diagnosed. People with FH have a 50% chance of passing it to their children and, without treatment, face a 50% risk of coronary heart disease by age 50 (men) or 60 (women).

FH is characterised by LDL cholesterol above 4.9 mmol/L, a strong family history of early heart disease, and sometimes physical signs including xanthomas (yellowish cholesterol deposits on tendons) and xanthelasma (around the eyes). If suspected, your GP should refer for specialist assessment and cascade genetic testing for family members.

Diagnosis: The NHS Cholesterol Blood Test

Cholesterol is measured via a simple blood test — a full lipid profile (total cholesterol, LDL, HDL, triglycerides, and non-HDL). The NHS recommends cholesterol testing for:

  • All adults as part of the NHS Health Check (ages 40–74)
  • Anyone with cardiovascular symptoms, diabetes, hypertension, or a family history of early heart disease or FH
  • Anyone starting certain medications (steroids, antiretrovirals, some antipsychotics)

NICE recommends a non-fasting sample for routine cholesterol testing — you do not need to starve beforehand. However, if triglycerides need to be measured, a fasting sample (9–12 hours without food) may be requested.

Cardiovascular Risk Assessment: QRISK3

Cholesterol levels alone don’t determine treatment. The NHS uses the QRISK3 calculator to estimate your 10-year risk of cardiovascular disease, taking into account cholesterol, blood pressure, age, ethnicity, BMI, smoking, diabetes, family history, deprivation, and other factors. NICE recommends offering statin treatment to people with a QRISK3 score of 10% or above (meaning at least a 1-in-10 chance of a heart attack or stroke in the next 10 years).

NHS Treatment for High Cholesterol

1. Lifestyle Changes

  • Diet — reduce saturated fat (replace with unsaturated fats: oily fish, olive oil, nuts, avocado); increase soluble fibre (oats, barley, pulses, apples, flaxseed); plant sterols and stanols (2g/day from fortified foods) lower LDL by 10–15%
  • Exercise — 150 minutes moderate activity per week raises HDL and lowers triglycerides
  • Weight loss — 5–10% body weight reduction can reduce LDL and triglycerides significantly
  • Stop smoking — raises HDL cholesterol
  • Reduce alcohol — particularly important for high triglycerides

2. Statins (First-Line Medication)

Statins are among the most prescribed drugs in the UK, taken by over 7 million people. They work by reducing the liver’s production of cholesterol and are proven to reduce heart attack and stroke risk by around 30% in high-risk individuals.

  • Atorvastatin 20mg — first-line NICE recommendation for primary prevention (QRISK3 ≥10%)
  • Atorvastatin 80mg — first-line NICE recommendation for secondary prevention (existing cardiovascular disease)
  • Rosuvastatin, simvastatin, pravastatin — alternatives

Common concerns about statins: The risk of serious muscle damage (rhabdomyolysis) is extremely rare (~1 in 10,000 users). “Statin intolerance” (muscle aches) occurs in 5–10% of users; switching statins or dose reduction usually resolves this. The evidence overwhelmingly supports statin use for high-risk patients despite minor side effects.

3. Non-Statin Options

  • Ezetimibe — reduces cholesterol absorption in the gut; often added to statins or used as an alternative in statin intolerance; reduces LDL by 15–20%
  • PCSK9 inhibitors (evolocumab, alirocumab) — injectable biologics reducing LDL by 50–60%; available on NHS for FH or statin intolerance with very high cardiovascular risk (NICE TA394, TA393)
  • Inclisiran — twice-yearly injection; approved by NICE in 2021 (TA733); works by silencing the PCSK9 gene
  • Bempedoic acid — oral tablet for statin-intolerant patients; NICE approved 2022
  • Fibrates (fenofibrate) — primarily for high triglycerides

UK Support and Resources

  • HEART UK — heartuk.org.uk | The UK’s cholesterol charity; cholesterol helpline: 0345 450 5988
  • British Heart Foundation — bhf.org.uk | Comprehensive cholesterol information and support
  • Familial Hypercholesterolaemia Society — fhsociety.org.uk | Support for people with FH
  • NICE CG181 — Cardiovascular disease: risk assessment and reduction, including lipid modification — full guideline at nice.org.uk

What Major Health Sites Often Miss About High Cholesterol

1. QRISK3 and the UK’s Whole-Person Risk Assessment Approach

US health sites focus heavily on cholesterol numbers in isolation. The UK’s QRISK3 system takes a more holistic view — incorporating social deprivation (Townsend score), systemic lupus erythematosus, severe mental illness, atrial fibrillation, and erectile dysfunction alongside traditional risk factors. This means a patient in a deprived area with type 2 diabetes may qualify for statin therapy even with borderline LDL levels.

2. The Underdiagnosis of Familial Hypercholesterolaemia

Only 8–15% of the 260,000 UK people with FH have been diagnosed. The NICE guideline recommends cascade testing — when one person is diagnosed with FH, all first-degree relatives should be offered genetic testing. If you or a close family member has had a heart attack before age 60, or has very high LDL despite a healthy lifestyle, ask your GP to assess for FH.

3. New Injectable Options Available on NHS

Inclisiran (Leqvio) — approved by NICE in 2021 and now part of NHS cardiovascular prevention strategy — is a twice-yearly injection for people with high LDL who are already on maximum tolerated statin therapy. This innovative siRNA therapy is now available on NHS prescriptions for eligible patients, yet many patients and even GPs are unaware of it.

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