Genetic testing for hypercholesterolemia is most useful for a person with very high low-density lipoprotein cholesterol despite a healthy lifestyle, a personal or family history of early heart attack or stroke, a family history of familial hypercholesterolemia, or a strong clinical suspicion based on cholesterol levels and physical examination findings. Testing is also valuable for first-degree relatives of someone already confirmed to carry a familial hypercholesterolemia gene change, since early identification allows treatment to start before arteries are significantly affected. In practice, a confirmed genetic diagnosis changes management by supporting earlier and more aggressive treatment decisions, guiding cascade testing of other family members, and providing clarity for long-term risk planning, including decisions around family planning. It also removes uncertainty for patients who might otherwise be told their high cholesterol is simply due to diet when the actual cause is inherited.