麻豆传媒

To get a picture of how much cholesterol you have circulating in your system that could deposit on your blood vessel walls and raise the risk for a heart attack or other event, blood tests are done to assess several major categories: the "bad" low-density lipoprotein (LDL) cholesterol, and the "good" high-density lipoprotein (HDL) cholesterol, along with triglycerides.

Direct measurement of LDL is difficult and expensive, so your doctors will usually rely on calculations based on total cholesterol and the other components. One exception is that this method of estimation doesn't work well at low LDL cholesterol levels (i.e., below 70 mg/dL). And if screening tests show a total cholesterol above the normal range (over 200 mg/dL), you might need more detailed testing.

Screening should start with a one-time cholesterol check at ages 9-11 years to catch dangerous genetic cholesterol disorders that could lead to early disease. Then for healthy individuals, cholesterol checks are recommended every 4-6 years starting around age 20. As age increases, screening becomes more frequent: every 2 years for men ages 45-65 and women ages 55-65, and every year after age 65 for both genders.

You might need to be checked more often if you are prescribed a medication to lower your cholesterol or have risk factors like a family history of high cholesterol or if you have diabetes, high blood pressure, heart disease, stroke, or blood flow problems to the legs or feet (peripheral artery disease).

Guidelines say that fasting before a screening cholesterol test isn't necessary for healthy adults age 20 and older who aren't taking medication to lower their cholesterol.

Follow the instructions of your healthcare team, though, because certain cholesterol tests do require that you don't eat or drink anything other than water for 8-2 hours before the test. The amount of cholesterol in a meal could influence triglyceride measurements, for example. Adults with a family history of premature heart disease from high cholesterol and those with a genetic cholesterol condition like familial hypercholesterolemia might also need to fast to get more precise results from their cholesterol tests.

Read previous installments in this series:

For Your Patients: Hypercholesterolemia: Understanding Your Diagnosis

For Your Patients: Why Do High Cholesterol Levels Matter?

For Your Patients: Who Gets Hypercholesterolemia?

"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.