High Cholesterol: What Your Numbers Actually Mean

You've had a cholesterol test and the numbers have come back. Total cholesterol 6.2. LDL 3.8. HDL 1.3. Triglycerides 1.9. Ratio 4.8. But what do any of these actually mean — and should you be worried?

If you're confused, you're not alone. Cholesterol results are among the most commonly misunderstood blood test findings in the UK, and six in ten adults have levels that are considered elevated. Let's break down what each number means, which ones matter most, and when you genuinely need to take action.

What Is Cholesterol?

Cholesterol is a waxy, fat-like substance that your body needs to build cells, produce hormones, and manufacture vitamin D. Your liver makes most of it — roughly 80% — and the rest comes from your diet.

The problem isn't cholesterol itself. The problem is having too much of the wrong type circulating in your blood for too long. Over time, excess cholesterol gets deposited inside artery walls, forming plaques that narrow blood vessels and eventually cause heart attacks and strokes.

Cholesterol travels through your bloodstream inside protein-coated packages called lipoproteins. The two main types — LDL and HDL — behave very differently, and understanding that difference is the key to making sense of your results.

Understanding Your Numbers

Here's what a standard UK lipid panel measures and what the NHS recommends:

Marker	Ideal Level	What It Means
Total cholesterol	Below 5 mmol/L	Sum of all cholesterol types
LDL cholesterol	Below 3 mmol/L	"Bad" cholesterol — drives plaque formation
HDL cholesterol	Above 1 mmol/L (men), above 1.2 mmol/L (women)	"Good" cholesterol — removes excess from arteries
Triglycerides	Below 2.3 mmol/L (non-fasting), below 1.7 mmol/L (fasting)	Fat in your blood, often linked to diet and metabolic health
Total:HDL ratio	Below 6 (ideally below 4)	Overall risk indicator

LDL cholesterol is the primary driver of atherosclerosis. Each LDL particle can penetrate your artery wall, get trapped, trigger inflammation, and contribute to plaque growth. The lower your LDL, the lower your risk — there is no threshold below which further reduction stops being beneficial.

HDL cholesterol acts as a scavenger, picking up excess cholesterol from artery walls and ferrying it back to the liver for disposal. Higher HDL is generally protective, though very high levels (above 2.3 mmol/L) don't necessarily confer additional benefit.

Triglycerides are the most diet-responsive component of your lipid panel. They spike after meals rich in sugar, refined carbohydrates, and alcohol. Persistently elevated triglycerides (above 2.3 mmol/L) are associated with increased cardiovascular risk, particularly when combined with low HDL and high LDL — a pattern sometimes called the atherogenic triad.

The Ratio That Matters

Your total cholesterol to HDL ratio (TC:HDL) is often a more useful indicator than total cholesterol alone. It captures the balance between harmful and protective lipoproteins.

For example, someone with a total cholesterol of 5.5 and an HDL of 1.8 has a ratio of 3.1 — which is excellent. Another person with the same total of 5.5 but an HDL of only 0.9 has a ratio of 6.1 — which flags significantly elevated risk.

Practical takeaway: Don't fixate on total cholesterol alone. A total of 5.8 with a great ratio may be less concerning than a total of 4.5 with a poor one. Always look at the full picture.

Beyond LDL: ApoB and Lp(a)

Standard lipid panels have served us well, but they have a blind spot. They measure the amount of cholesterol carried in LDL particles, not the number of particles themselves. Two people with identical LDL cholesterol can have very different particle counts — and particle count is a stronger predictor of risk.

Apolipoprotein B (ApoB) counts every atherogenic particle in your blood. The European Society of Cardiology now recommends ApoB as a superior risk marker. If your LDL is borderline but you have metabolic syndrome, insulin resistance, or high triglycerides, ApoB testing can reveal hidden risk that standard panels miss.

Lipoprotein(a), or Lp(a), is a genetically determined particle that significantly increases cardiovascular risk. It's worth testing at least once in your lifetime, because levels are largely determined by your DNA rather than your lifestyle. Around 20% of the population has elevated Lp(a), and most have never been tested.

Neither ApoB nor Lp(a) is included in standard NHS cholesterol testing. Private blood panels that include these advanced markers provide a more complete cardiovascular picture.

What Causes High Cholesterol?

High cholesterol has both modifiable and non-modifiable causes:

Non-modifiable factors

• Genetics — familial hypercholesterolaemia (FH) affects about 1 in 250 people in the UK, causing very high LDL from birth. If a parent, sibling, or child has had a heart attack before 55 (men) or 65 (women), FH screening is important
• Age — cholesterol levels naturally rise with age, particularly in women after menopause
• Sex — men tend to have higher LDL and lower HDL than pre-menopausal women

Modifiable factors

• Diet high in saturated fat — fatty meat, full-fat dairy, butter, pastries, and coconut oil
• Excess body weight — particularly visceral fat around the abdomen
• Physical inactivity — exercise raises HDL and improves particle composition
• Smoking — lowers HDL and damages artery walls, making them more susceptible to cholesterol deposits
• Excessive alcohol intake — raises triglycerides and contributes to liver dysfunction
• Type 2 diabetes — closely linked to the atherogenic triad of high triglycerides, low HDL, and small dense LDL

Treatment Options

Lifestyle changes

These are always the first line, regardless of your numbers:

• Dietary improvements — reduce saturated fat, increase soluble fibre (oats, beans, lentils), eat more oily fish, use olive oil instead of butter
• Regular exercise — at least 150 minutes of moderate-intensity activity per week; particularly effective at raising HDL
• Weight management — losing 5–10% of body weight improves your entire lipid profile
• Smoking cessation — HDL levels begin to recover within weeks of quitting
• Moderate alcohol intake — no more than 14 units per week, spread across several days

Medication

NICE guidelines recommend statin therapy when lifestyle changes alone are insufficient, particularly if your 10-year cardiovascular risk (QRISK3) is 10% or greater. Statins reduce LDL by 30–50%. Additional options include ezetimibe, PCSK9 inhibitors, and bempedoic acid for those who can't tolerate statins.

Lifestyle Changes That Work

If you want to move the needle without medication — or alongside it — these strategies have the strongest evidence:

• Swap saturated fats for unsaturated fats — olive oil, avocado, nuts, and oily fish in place of butter, cheese, and processed meats
• Eat 3g of beta-glucan daily — found in oats and barley. This alone can reduce LDL by 5–10%
• Add plant stanols and sterols — available in fortified yoghurts and spreads; 2g daily reduces LDL by up to 10%
• Eat at least 5 portions of fruit and vegetables daily — the fibre, antioxidants, and phytochemicals all contribute
• Stay active — combine aerobic exercise (brisk walking, cycling, swimming) with resistance training for the best lipid improvements

Practical takeaway: Diet and exercise changes typically take 8–12 weeks to show up in blood results. Get retested after three months of consistent lifestyle change to see the impact before considering medication.

When to Get Tested

The NHS Health Check programme invites adults aged 40–74 for a cardiovascular risk assessment every five years, which includes a cholesterol check. However, five-year gaps leave a lot of time for changes to go unnoticed.

Consider testing sooner — or more frequently — if you:

• Have a family history of high cholesterol or early heart disease
• Are overweight or have a large waist circumference (above 94 cm for men, 80 cm for women)
• Have type 2 diabetes or pre-diabetes
• Have high blood pressure
• Smoke or have recently quit
• Have already been diagnosed with elevated cholesterol and want to track your response to treatment

A comprehensive lipid panel — ideally including ApoB and Lp(a) alongside the standard markers — gives you the clearest possible picture of your cardiovascular risk. It's one of the most straightforward, evidence-based steps you can take to protect your long-term health.

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