Familial hypercholesterolaemia (FH)—an inherited genetic defect that causes high blood cholesterol—often goes unrecognised. It is therefore under-diagnosed and poorly managed. This can have devastating repercussions for affected families, since premature deaths from heart disease can occur in people in their 40s or even younger. This article looks at the causes of FH, how to recognise those at risk and how to implement National Institute for Health and Clinical Excellence (NICE) guidance in practice.