Cholesterol — Total Cholesterol, LDL & HDL

What is cholesterol?

Cholesterol is a waxy, fat-like substance (a lipid) that the body both produces (primarily in the liver) and absorbs from food. Far from being simply harmful, cholesterol is essential for life — it is a core component of every cell membrane, a precursor for steroid hormones (including testosterone, oestrogen, and cortisol), and the starting material for vitamin D synthesis and bile acid production.

Because cholesterol cannot dissolve in blood, it is packaged into protein-coated particles called lipoproteins for transport. The two most clinically important lipoproteins are:

• LDL (low-density lipoprotein) — often called "bad" cholesterol; carries cholesterol from the liver to peripheral tissues; excess LDL can deposit cholesterol in artery walls, forming atherosclerotic plaques that narrow arteries and increase heart attack and stroke risk
• HDL (high-density lipoprotein) — often called "good" cholesterol; transports cholesterol from artery walls back to the liver for disposal (reverse cholesterol transport); higher HDL levels are protective against cardiovascular disease

A standard lipid profile measures total cholesterol, LDL, HDL, non-HDL cholesterol (total minus HDL — a useful cardiovascular risk marker), and triglycerides. Together, these provide a detailed picture of cardiovascular risk that no single figure alone can offer. LDL is currently the primary therapeutic target in cardiovascular prevention guidelines.

Normal cholesterol ranges

UK guidelines (NICE / HEART UK) recommend the following desirable levels for adults:

• Total cholesterol: <5.0 mmol/L (desirable); >6.0 mmol/L is raised
• LDL cholesterol: <3.0 mmol/L (ideally); >4.0 mmol/L is elevated; >5.0 mmol/L significantly raised
• HDL cholesterol: >1.0 mmol/L in men, >1.2 mmol/L in women (higher is protective); <1.0 mmol/L is a risk factor
• Non-HDL cholesterol (Total − HDL): <4.0 mmol/L (desirable)
• Total:HDL ratio: <4.0 (lower is better)

For those with established cardiovascular disease, type 2 diabetes, or familial hypercholesterolaemia, lower LDL targets apply (typically <2.0 or even <1.8 mmol/L). Discuss target levels with your clinician based on your full cardiovascular risk profile.

What high cholesterol may indicate

Raised total and/or LDL cholesterol increases the long-term risk of atherosclerosis and cardiovascular events. Common causes of elevated cholesterol include:

• Diet high in saturated and trans fats — red meat, processed foods, full-fat dairy, and tropical oils raise LDL cholesterol; dietary modification is the first-line intervention
• Familial hypercholesterolaemia (FH) — an inherited condition causing very high LDL from birth; affects approximately 1 in 250 people in the UK; typically requires medication alongside dietary changes
• Physical inactivity and obesity — lower HDL and raise LDL and triglycerides; modest weight loss and regular aerobic exercise meaningfully improve the lipid profile
• Hypothyroidism — an underactive thyroid reduces LDL clearance; cholesterol falls significantly once thyroid hormone levels are corrected
• Type 2 diabetes and insulin resistance — typically raises triglycerides, lowers HDL, and produces small dense LDL particles that are particularly atherogenic

What low cholesterol or low HDL may indicate

A low total cholesterol in an otherwise healthy person is generally a positive finding and warrants no action. Specific findings to note:

• Very low total cholesterol (<3.0 mmol/L) — occasionally associated with hyperthyroidism, liver disease, malnutrition, or malignancy; warrants investigation in context
• Low HDL cholesterol — below 1.0 mmol/L in men or 1.2 mmol/L in women; an independent cardiovascular risk factor; associated with metabolic syndrome, type 2 diabetes, smoking, physical inactivity, and hypertriglyceridaemia
• Very low LDL on statin therapy — not inherently harmful; current evidence supports LDL levels well below 1.0 mmol/L as safe in high-risk individuals on treatment
• High HDL (>2.0 mmol/L) — generally protective; very high HDL (>2.5 mmol/L) may occasionally be associated with dysfunctional HDL but is not routinely investigated

Get your cholesterol tested at The Vesey

A full lipid profile (total cholesterol, LDL, HDL, non-HDL, and triglycerides) is available at The Vesey Private Hospital, Sutton Coldfield, as part of:

• Lipids & HbA1c Panel — £149 (full lipid profile + HbA1c — ideal cardiovascular and metabolic health screen)
• Heart Health Panel — comprehensive cardiovascular assessment including lipids, CRP, and blood pressure review
• Lifestyle Screen — multi-system panel including lipids, blood count, liver, kidney, and thyroid function
• Advanced Health Panels — full metabolic and organ-function assessment

Fasting recommended: Please fast for 10–12 hours before your appointment (water is fine) for the most accurate triglyceride and LDL results. Morning fasting appointments are available from 8am, 7 days a week.

Frequently asked questions

Further reading: Cholesterol — Lab Tests Online UK · Independent patient information from the British Society for Clinical Biochemistry.