A cholesterol result lands in your patient record and the doctor says it is a bit high. You leave the appointment with a number and no real understanding of what it means, whether it matters for you specifically, or what happens next.
This is an extremely common experience. UK laboratories report five or six separate values in a full lipid profile, and most people have no framework for understanding what each one does, which ones drive cardiovascular risk, and which ones are essentially background information.
- What cholesterol actually is
- The UK lipid profile explained
- What is considered high cholesterol in the UK
- LDL: the marker that matters most
- HDL: why higher is better
- Non-HDL cholesterol: the number clinicians prefer
- Triglycerides: the overlooked marker
- When statins are actually recommended in the UK
- What a total cholesterol reading misses
- Check your lipid profile results
What cholesterol actually is
Cholesterol is a fatty substance produced mostly by the liver. Every cell in the body needs it. It is essential for making hormones including oestrogen, testosterone, and cortisol, for producing vitamin D, and for maintaining cell membrane structure. The problem is not cholesterol itself but the way it is transported around the body and what happens when too much of certain types accumulates.
Cholesterol travels through the blood packaged inside proteins called lipoproteins. Different types of lipoprotein carry cholesterol in different directions and behave very differently in terms of cardiovascular risk.
The UK lipid profile explained
A standard fasting lipid profile in the UK reports the following:
| Marker | What it measures |
|---|---|
| Total cholesterol | All cholesterol fractions combined |
| LDL cholesterol | Low-density lipoprotein cholesterol |
| HDL cholesterol | High-density lipoprotein cholesterol |
| Non-HDL cholesterol | Total cholesterol minus HDL |
| Triglycerides | Circulating blood fats |
| TC:HDL ratio | Total cholesterol divided by HDL |
Some reports also include a calculated VLDL (very low-density lipoprotein) value, but this is not universally reported and is not a direct treatment target.
A non-fasting sample is now acceptable for initial cardiovascular risk screening. A fasting sample is still used for more accurate triglyceride measurement and in people with known high triglycerides.
What is considered high cholesterol in the UK
The NHS reference ranges and clinical thresholds are as follows:
Total cholesterol
| Level | Category |
|---|---|
| Below 5.0 mmol/L | Desirable for most adults |
| 5.0 to 6.4 mmol/L | Mildly raised |
| 6.5 to 7.8 mmol/L | Moderately raised |
| Above 7.8 mmol/L | Severely raised |
More than half of UK adults have a total cholesterol above 5.0 mmol/L. On its own, this number tells you relatively little about your actual risk.
LDL cholesterol
| Level | Category |
|---|---|
| Below 3.0 mmol/L | Optimal for most adults |
| 3.0 to 4.9 mmol/L | Raised |
| Above 4.9 mmol/L | Significantly raised, possible familial hypercholesterolaemia |
HDL cholesterol
| Level | Category |
|---|---|
| Above 1.2 mmol/L (women) / 1.0 mmol/L (men) | Acceptable |
| Below 1.0 mmol/L | Low, increases cardiovascular risk |
Triglycerides (fasting)
| Level | Category |
|---|---|
| Below 1.7 mmol/L | Optimal |
| 1.7 to 5.6 mmol/L | Raised |
| Above 10.0 mmol/L | Very high, acute pancreatitis risk |
Non-HDL cholesterol
| Level | Category |
|---|---|
| Below 4.0 mmol/L | Desirable for most adults |
| Above 4.0 mmol/L | Warrants clinical attention |
LDL: the marker that matters most
LDL, low-density lipoprotein, carries cholesterol from the liver to tissues around the body. When LDL concentration is high, excess cholesterol is deposited into artery walls, forming plaques. This process, atherosclerosis, is the underlying cause of most heart attacks and strokes.
This is why LDL is the primary target of lipid-lowering treatment. Reducing LDL consistently reduces cardiovascular events. The relationship is well established across decades of trial data.
Familial hypercholesterolaemia (FH) is a genetic condition that causes very high LDL levels from birth. It affects around 1 in 250 people in the UK and is significantly under-diagnosed. An LDL above 4.9 mmol/L, or a total cholesterol above 7.5 mmol/L, particularly in a younger person or one with a family history of early heart disease, should prompt consideration of FH screening.
HDL: why higher is better
HDL, high-density lipoprotein, moves cholesterol away from artery walls and back to the liver for processing and excretion. It works in the opposite direction to LDL. Higher HDL is associated with lower cardiovascular risk.
A low HDL, below 1.0 mmol/L in men or below 1.2 mmol/L in women, independently increases cardiovascular risk even when LDL looks acceptable. This is one reason total cholesterol in isolation is not a useful guide. A person with total cholesterol of 5.2 mmol/L but an HDL of 0.8 mmol/L is at higher risk than someone with total cholesterol of 6.0 mmol/L and an HDL of 1.8 mmol/L.
HDL levels are influenced by physical activity, smoking, and alcohol intake, in addition to genetic factors. Regular aerobic exercise is one of the most effective ways to raise HDL. Smoking lowers it. Heavy alcohol use can raise HDL modestly, but this does not translate into clinical benefit.
Non-HDL cholesterol: the number clinicians prefer
Non-HDL cholesterol is total cholesterol minus HDL. It captures all the atherogenic, meaning artery-damaging, lipoprotein particles: LDL, VLDL, and IDL. It does not require a fasting sample to be accurate, and it is increasingly preferred as a treatment target over LDL alone.
NICE guidelines use non-HDL cholesterol as a co-primary target alongside LDL in people on lipid-lowering therapy. The treatment target for non-HDL in people with established cardiovascular disease is below 2.5 mmol/L. For primary prevention, below 4.0 mmol/L is the general threshold for clinical attention.
If you are given a single number to track, non-HDL is arguably more informative than total cholesterol.
Triglycerides: the overlooked marker
Triglycerides are the storage form of fat in the body. After a meal, the liver packages excess calories as triglycerides and releases them into the bloodstream. Persistently raised triglycerides, above 1.7 mmol/L fasting, are associated with increased cardiovascular risk, particularly when combined with low HDL and raised non-HDL.
The conditions most associated with high triglycerides are:
- Type 2 diabetes and insulin resistance
- Obesity
- Excessive alcohol intake
- Hypothyroidism
- Chronic kidney disease
- Certain medications including corticosteroids, retinoids, and some antipsychotics
Triglycerides above 10.0 mmol/L carry a specific risk of acute pancreatitis, a serious and potentially life-threatening condition. At this level, urgent treatment to lower triglycerides is warranted, regardless of overall cardiovascular risk.
When statins are actually recommended in the UK
This is where many people have a misconception. In the UK, statins are not prescribed based on a specific LDL or total cholesterol threshold. They are prescribed based on your 10-year risk of a cardiovascular event, primarily calculated using a risk tool called QRISK3.
QRISK3 combines your cholesterol results with your age, sex, blood pressure, smoking status, BMI, deprivation index, family history, and the presence of conditions such as type 2 diabetes, atrial fibrillation, and chronic kidney disease. The output is a percentage risk of having a heart attack or stroke in the next 10 years.
The current NICE guidance is that statins should be offered to people with a 10-year cardiovascular risk of 10% or more for primary prevention, meaning people who have not yet had a cardiovascular event. This threshold captures a broad population rather than focusing narrowly on cholesterol levels.
For people with established cardiovascular disease, meaning those who have already had a heart attack, stroke, or TIA, or who have peripheral arterial disease, the treatment targets are considerably more stringent:
- LDL below 1.4 mmol/L
- Non-HDL below 2.5 mmol/L
- At least a 50% reduction in LDL from baseline
These targets often require high-intensity statins, and sometimes additional agents such as ezetimibe or PCSK9 inhibitors, to achieve.
The practical implication is that a raised cholesterol in isolation does not mean statins are appropriate for you. It also means that someone with a normal-looking cholesterol but multiple other risk factors may have a high 10-year risk and may benefit from treatment. Both scenarios are common, and both require the full risk calculation rather than a cholesterol number alone.
What a total cholesterol reading misses
The single total cholesterol number that often gets reported in summary form, or mentioned in passing by a GP, is the least informative marker in the panel. It can be misleading in either direction.
High total cholesterol driven by high HDL, which is sometimes seen in endurance athletes, carries no increased risk. The HDL component is protective. Conversely, total cholesterol that sits at 5.0 mmol/L with low HDL, raised triglycerides, and raised non-HDL indicates a significantly adverse lipid pattern despite looking unremarkable.
The TC:HDL ratio is a better single summary number than total cholesterol. A ratio below 4.0 is generally considered acceptable. Above 6.0 is associated with substantially elevated risk.
If you have been given a total cholesterol number without the full breakdown, it is worth requesting the full lipid panel from your GP surgery or clinic. Most practices can provide this from the same blood sample.
Check your lipid profile results
If you have your full lipid panel results, the free blood test explainer covers all six lipid markers. Enter your values to see where each one sits against the reference range and get a plain-English explanation of what the pattern means, including the TC:HDL ratio and non-HDL figure.
The lipid panel is one of eight covered in the tool, alongside FBC, liver function, thyroid, kidney function, HbA1c, iron studies, and bone profile.
Explore the free blood test explainer
This article is for general information only. It is not a substitute for clinical assessment. Your GP or practice nurse can calculate your full cardiovascular risk score and advise on whether treatment is appropriate for you.
