Cholesterol, necessary for cell membranes and steroid hormone synthesis, and triglyceride (TG), essential for energy generation and storage, are transported on lipoproteins. Circulating cholesterol is mostly on low-density lipoproteins (LDLs) and TG on very low-density lipoproteins (VLDLs) and chylomicrons. Excessive concentrations of LDL cholesterol (LDLc) and TG can be harmful, leading to atherosclerotic cardiovascular disease (ASCVD), which is preventable by treatment. Heterozygous familial hypercholesterolemia is a dominantly inherited cause of hypercholesterolemia detectable in childhood. It affects 1 in 250–500 people. Even commoner is hypercholesterolemia due to a genetic predisposition combined with acquired, frequently nutritional, factors such as obesity, often referred to as polygenic hypercholesterolemia. Hypertriglyceridemia, particularly when associated with diabetes, compounds the risk of ASCVD and when severe can cause recurrent episodes of acute pancreatitis.