HDL (high-density lipoprotein) cholesterol is often called the 'good' cholesterol because it plays a protective role in cardiovascular health. HDL particles collect excess cholesterol from the artery walls and peripheral tissues and transport it back to the liver for reprocessing or excretion — a process known as reverse cholesterol transport.

Higher HDL levels are associated with reduced cardiovascular risk. Low HDL (below 1.0 mmol/L in men and 1.3 mmol/L in women) is an independent risk factor for heart disease and is strongly associated with insulin resistance, metabolic syndrome, obesity, smoking, and a sedentary lifestyle. Exercise, moderate alcohol consumption, and omega-3 fatty acids are among the most effective ways to raise HDL.