Statins work by inhibiting an enzyme called HMG-CoA reductase, which is involved in the production of cholesterol in the liver. By blocking this enzyme, statins reduce the amount of cholesterol that is produced in the liver and increase the liver's ability to remove LDL (low-density lipoprotein) cholesterol from the blood. This leads to a decrease in total cholesterol levels, including LDL cholesterol, and a modest increase in HDL (high-density lipoprotein) cholesterol levels. Statins are commonly used to treat high cholesterol and reduce the risk of cardiovascular disease.