Dyslipidaemias are alterations to the plasma lipid profile that are often associated with clinical conditions. Dyslipidaemias, particularly elevated plasma LDL-cholesterol levels, are major risk factors for cardiovascular disease, but some forms, such as hypertriglyceridaemia, are associated with severe diseases in other organ systems, including non-alcoholic fatty liver disease and acute pancreatitis. Dyslipidaemias can be genetically determined (primary or familial dyslipidaemias) or secondary to other conditions (such as diabetes mellitus, obesity or an unhealthy lifestyle), the latter being more common. Hypercholesterolaemia is the most common form of dyslipidaemia and is associated with an increased risk of cardiovascular disease, with elevated plasma LDL-cholesterol levels being the 15th leading risk factor for death in 1990, rising to 11th in 2007 and 8th in 2019. The global burden of dyslipidaemias has increased over the past 30 years. Furthermore, the combination of high triglyceride levels and low HDL-cholesterol levels (together with the presence of small, dense LDL particles), referred to as atherogenic dyslipidaemia, is highly prevalent in patients with diabetes or metabolic syndrome and increases their risk of cardiovascular disease. Given the increasing prevalence of diabetes worldwide, treating lipid abnormalities in these patients might reduce their risk of cardiovascular disease.