High-density lipoproteins (HDL) are plasma lipoproteins responsible for transporting cholesterol from peripheral tissues back to the liver for excretion, a process known as reverse cholesterol transport. Clinically, HDL levels are important because higher concentrations are associated with a reduced risk of atherosclerotic cardiovascular disease, reflecting their protective role against plaque formation. Low HDL is commonly linked to increased risk of coronary artery disease and is a target for cardiovascular risk assessment and management.