HDL Cholesterol (Good Cholesterol) Test

What Is HDL Cholesterol?

High-density lipoprotein (HDL) cholesterol is often called the 'good' cholesterol because it helps remove excess cholesterol from your bloodstream and transport it to your liver for elimination. In my clinical practice, I frequently remind patients that HDL acts like a garbage truck, sweeping away harmful LDL cholesterol from artery walls. This process reduces the risk of plaque buildup, heart attacks, and strokes.

The standard laboratory name for this test is HDL Cholesterol (HDL-C), and it is measured in milligrams per deciliter (mg/dL) or millimoles per litre (mmol/L). The LOINC code for this analyte is 2085-9, which ensures consistent identification across healthcare systems worldwide.

Why Is HDL Cholesterol Important?

Numerous large-scale studies have shown that higher HDL levels are associated with a lower risk of cardiovascular disease. HDL particles have anti-inflammatory, antioxidant, and anti-clotting properties. They also promote the removal of cholesterol from macrophage cells in the arterial wall, a process called reverse cholesterol transport.

My patients often ask, 'If my LDL is low, do I still need to worry about HDL?' The answer is yes—low HDL is an independent risk factor for heart disease, even when other lipids are normal. Aiming for an HDL level above 40 mg/dL (1.0 mmol/L) for men and above 50 mg/dL (1.3 mmol/L) for women is a good starting target.

Reference Ranges for HDL Cholesterol

Optimal levels vary by age, sex, and population. The following table summarises typical reference ranges used in UK and US laboratories.

Note: Values may differ slightly between laboratories. Always interpret results with your clinician.

How to Raise HDL Cholesterol Naturally

If your HDL is low, here are evidence-based strategies I recommend to my patients:

• Exercise regularly: Aerobic activity (brisk walking, jogging, cycling) for at least 150 minutes per week can boost HDL by 5–10%.
• Choose healthy fats: Olive oil, avocados, nuts, and fatty fish (salmon, mackerel) provide monounsaturated and omega-3 fats that support HDL production.
• Stop smoking: Within weeks of quitting, HDL levels often rise by 5–10%.
• Maintain a healthy weight: Excess belly fat is strongly linked to low HDL. Losing even 5–10% of body weight can help.
• Moderate alcohol intake: If you drink, up to one drink per day for women and two for men may raise HDL. However, this is not a recommendation to start drinking.

Can Supplements Raise HDL?

Some patients ask about niacin or fibrates. While niacin (vitamin B3) can increase HDL by 15–35%, it may cause unpleasant flushing and liver side effects. Fibrates (gemfibrozil, fenofibrate) also raise HDL modestly but are reserved for high-risk individuals. I advise against taking these without medical supervision—lifestyle changes remain the safest first step.

Is High HDL Dangerous?

Very high HDL (above 80–100 mg/dL) is uncommon and may actually be harmful in some cases. Genetic disorders like cholesteryl ester transfer protein (CETP) deficiency can cause extremely high HDL levels that do not function properly. Recent research suggests that 'too high' HDL (> 90 mg/dL) may paradoxically increase cardiovascular risk in certain populations. If your HDL is consistently above 100 mg/dL, further testing (e.g., apolipoprotein A1, HDL function assays) may be warranted.

HDL During Pregnancy

During pregnancy, HDL levels typically rise 15–25% due to hormonal changes (oestrogen increases HDL production). In the second and third trimesters, levels of 45–65 mg/dL are common. This physiological rise is normal and not a cause for concern. After delivery, HDL gradually returns to pre-pregnancy levels.

What Affects HDL Test Results?

• Fasting: While HDL is less affected by food than triglycerides, many labs still recommend a 9–12 hour fast for a full lipid panel.
• Medications: Beta-blockers, anabolic steroids, and some diuretics can lower HDL. Statins have a minimal effect.
• Acute illness or stress: Hospitalisation, infection, or surgery can temporarily alter lipid levels.

When Should You Test HDL Cholesterol?

Screening for adults begins at age 20 and should be repeated every 4–6 years if levels are normal. More frequent testing is indicated if you have diabetes, hypertension, family history of early heart disease, or if you are on lipid-lowering therapy. I also check lipids earlier in patients with obesity or metabolic syndrome.

Bottom Line

HDL cholesterol is a key marker of cardiovascular health. A low HDL level should prompt a conversation about lifestyle modifications. While medications can help, the foundational steps—exercise, diet, smoking cessation, and weight management—remain the most effective and safe ways to boost your good cholesterol. If you have concerns about your lipid profile, please discuss them with your healthcare provider.