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Heart & Vascular

HDL Cholesterol

HDL is the 'good' cholesterol that carries excess cholesterol back to your liver.

What is HDL Cholesterol?

HDL cholesterol is the cholesterol carried back to the liver inside HDL particles. This reverse transport gave HDL its 'good' or 'protective' reputation. But HDL is not a lever to pull — it is a marker to read in context. HDL behaves differently from LDL or ApoB, where lower is reliably better. With HDL the relationship is not linear: too low is unfavourable, but very high does not add protection. Always read HDL alongside LDL, triglycerides, ApoB, and your metabolic profile.

Why is HDL Cholesterol relevant?

Low HDL consistently tracks with more cardiovascular events in large population studies. But drugs that pharmacologically raised HDL did not lower cardiovascular risk. A low HDL is better read as a flag for what usually travels with it — insulin resistance, high triglycerides, physical inactivity, smoking, and excess abdominal fat — rather than as a defect to fix in isolation. The levers most consistently linked to higher HDL are also worth pursuing for their broader effects: regular endurance exercise, losing excess weight, stopping smoking, and choosing healthier fats. Higher HDL is a by-product of better metabolic health — not the target itself.

HDL Cholesterol high or low — what it means

Always read HDL alongside LDL, triglycerides, and ApoB. A favourable HDL paired with high triglycerides or a high ApoB is not reassurance — the company HDL keeps is what matters. A high triglyceride/HDL ratio is a practical pointer toward insulin resistance. A low HDL almost always travels with an unfavourable metabolic pattern — addressing that pattern is the meaningful response, not chasing the number itself. A very high HDL is not automatically better; at the extreme upper end some large cohort studies show slightly elevated risks. Track the trend across repeat measurements.

HDL Cholesterol reference ranges

Men (favourable)Below 1.0 mmol/L is flagged as low / increased risk in men (NHG; ≈ 40 mg/dL)≥ 1.0 mmol/L
Women (favourable)Below 1.2 mmol/L is flagged as low / increased risk in women (NHG); 1.3 mmol/L (50 mg/dL) comes from international and metabolic-syndrome criteria≥ 1.2 mmol/L
Extra favourableGenerally regarded as extra favourable for both sexes (NVKC: >1.55 mmol/L = low risk)≥ 1.6 mmol/L
Plateau / no further gain≈ 80–90 mg/dL; no demonstrable added protection above this. Only at the extreme upper end (from ≈ 2.5 mmol/L) do large cohorts link very high HDL to slightly higher mortality≈ 2.0–2.3 mmol/L

Cut-offs vary by lab and method. In the Netherlands reported in mmol/L (1 mmol/L ≈ 39 mg/dL). HDL is never read alone — always alongside LDL, triglycerides and ApoB.

Educational information only — not medical advice. Consult a healthcare professional for clinical decisions.

Read about our scientific approach →Read the guide: Heart health →

Frequently asked questions

What is a normal HDL cholesterol level?

As a general, lab-dependent reference, an HDL of roughly 1.0 mmol/L or higher in men and 1.2–1.3 mmol/L or higher in women (about 40 and 45–50 mg/dL) is considered favourable. Dutch (NHG) guidance flags HDL below 1.0 mmol/L in men and below 1.2 mmol/L in women as a marker of increased risk. A value from about 1.6 mmol/L upward is usually seen as extra favourable. This is a reference point, not a diagnosis — always read HDL alongside LDL, triglycerides and ApoB.

What does a low HDL level mean?

A low HDL (below 1.0 mmol/L in men, below 1.2 mmol/L in women) tracks with more cardiovascular events across large populations. It usually travels with a metabolic pattern: insulin resistance, high triglycerides, excess abdominal fat, inactivity and smoking. So a low HDL is best read as a flag for that underlying pattern — not a defect to fix in isolation. Drugs that pharmacologically raised HDL did not, in fact, lower cardiovascular risk.

Can HDL be too high, and when is it concerning?

Higher is not always better: the relationship is U-shaped. Above roughly 2.0–2.3 mmol/L (around 80–90 mg/dL) there is no demonstrable added protection. Only at the extreme upper end — from about 2.5 mmol/L — do several large cohorts link very high HDL to slightly higher all-cause mortality. A very high HDL can also reflect heavy alcohol use or a genetic variant — a reason for calm attention rather than alarm.

How do I raise my HDL?

The levers most consistently linked to higher HDL are regular endurance exercise, losing excess weight, stopping smoking and replacing refined carbohydrates with healthier fats. A higher HDL is mainly a by-product of better metabolic health, not a target in itself. Always read HDL alongside LDL, triglycerides and ApoB, and follow the trend across repeat measurements.

Related biomarkers

LDL Cholesterol
LDL cholesterol is the cholesterol in your blood that can lodge in artery walls and build up as plaque.
Triglycerides
Triglycerides are a blood fat that responds strongly to diet and alcohol and reflects your metabolic health.
Apolipoprotein B (ApoB)
ApoB is a protein on every harmful cholesterol particle, so it counts how many of those particles circulate in your blood.
Total Cholesterol
Total cholesterol is the sum of all the cholesterol in your blood and the starting point of the lipid profile.

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