HDL Cholesterol
High-density lipoprotein – the 'good' cholesterol
Also known as
Definition
HDL cholesterol facilitates reverse cholesterol transport by shuttling excess cholesterol from arterial walls back to the liver. High HDL levels are considered cardioprotective, although HDL function (cholesterol efflux capacity) matters more than the measured value alone. Regular physical activity and smoking cessation sustainably raise HDL levels.
| Parameter | Value |
|---|---|
| Unit | mg/dl (mmol/l) |
| Reference Range | Women: > 50 mg/dl | Men: > 40 mg/dl |
| Optimal Range (lab2go) | Women: > 60 mg/dl | Men: > 55 mg/dl (lab2go Optimum Zone) |
Conversion: 1 mg/dl × 0.02586 = mmol/l. US labs report mg/dl; international studies also use mmol/l.
↓ What a low value means
Low HDL (< 40 mg/dl men, < 50 mg/dl women) is an independent risk factor for heart attack and stroke. Causes: physical inactivity, smoking, obesity, hypertriglyceridemia (HDL and triglycerides move inversely), type 2 diabetes, metabolic syndrome, genetic hypoalphalipoproteinemia. Low HDL combined with high triglycerides and high ApoB is particularly atherogenic.
↑ What a high value means
Very high HDL (> 80–100 mg/dl) is not necessarily protective — clinical studies show U-shaped curves. Extreme values (> 100 mg/dl) may indicate rare genetic disorders (CETP deficiency, cholestasis), dysfunctional HDL, or measurement error. Moderately high HDL (60–80 mg/dl) from exercise is cardioprotective.
✓ How to optimize this marker
Exercise: aerobic training (at least 150 min/week) raises HDL most effectively (+3–10 mg/dl). Quit smoking (+2–5 mg/dl rise). Omega-3 fatty acids (fish, flaxseed oil) can modestly raise HDL. Weight loss in obesity. Avoid trans fats.
When to test
In the lipid panel always with total cholesterol, LDL, and triglycerides. For precise triglyceride measurement: 12 hours fasting; HDL is not fasting-dependent. Screening from age 35 (men), age 45 (women), or earlier with cardiovascular risk factors. Follow-up every 3–5 years with normal values.
Frequently asked questions
Can HDL be too high? +
Yes. With HDL > 80–100 mg/dl, large studies show no additional protection — some even show mildly elevated mortality. HDL function (efflux capacity) is more important than the raw value. Very high values from exercise are, however, unproblematic.
How much does exercise raise HDL? +
Regular aerobic training (4–5 × 30–45 min/week) raises HDL by an average of 3–10 mg/dl within 3–6 months. Strength training has a smaller but present effect.
What is the relationship between HDL and triglycerides? +
HDL and triglycerides are metabolically linked via CETP (cholesteryl ester transfer protein). High triglycerides lower HDL (triglyceride-HDL exchange). Low HDL + high triglycerides is a central feature of metabolic syndrome.
Sources
Last Reviewed: May 28, 2026 · sina
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.