High cholesterol diagnosis

What is a cholesterol test?

Cholesterol is typically tested through blood work⁹, and most routine blood tests include cholesterol levels.

Since there are usually no symptoms of high cholesterol, it is all the more important to schedule routine tests with your provider. This is especially pertinent for individuals with a family history of high cholesterol or other conditions that increase the risk for it.

In order to get accurate results, you may need to fast (not eat or drink) for anywhere between 8–12 hours before the test. Before the day of your blood test, be sure to ask your provider how best to prepare. Try to follow your provider’s pre-test instructions as best as you can to ensure the accuracy of your results.

What your cholesterol test means

A cholesterol test—also known as a lipid profile or lipid panel—calculates the levels of different types of lipids or fats in the blood.

The test will show your levels of good (HDL) cholesterol, bad (LDL) cholesterol, and total cholesterol levels. It also measures your triglycerides, another type of lipoprotein in the blood produced when your body converts calories it doesn’t immediately need for energy into fat cells.

Cholesterol is measured in milligrams per deciliter of blood (mg/dL). Diagnosis of high cholesterol depends on LDL cholesterol content, or LDL-C (see LDL and HDL Cholesterol: What’s the Difference? above).

For most people, an optimal level of LDL-C is at or below 100 mg/dL. LDL-C levels become less desirable above 100 mg/dL, but the proper diagnosis of high cholesterol requires taking into account other risk factors¹⁰ in conjunction with the raw measurement of LDL-C. These factors include:

• Older age (for males, 45 and older; for females, 55 and older)
• Family history of premature atherosclerotic cardiovascular disease (55 and younger in males; 65 and younger in females)
• Hypertension
• Diabetes
• Smoking
• Low HDL cholesterol levels (less than 40 mg/dL in males; less than 55 mg/dL in females)

With at least two of the above risk factors, high cholesterol is defined as having an LDL-C greater than 130 mg/dL. With only one of the above risk factors, the LDL-C minimum threshold for high cholesterol is raised to 160 mg/dL. For individuals with none of the above risk factors, the minimum threshold is raised to 190 mg/dL.

When should you get a cholesterol test?

The CDC and the U.S. Department of Health recommend that every adult age 18 and older should get a cholesterol level screening every 4–6 years. Certain risk factors may encourage more frequent screening, such as:

• Familial history of cardiovascular disease
• Obesity
• Diabetes
• Smoking
• A previous abnormal cholesterol test result

As you age, you should also get tested more frequently. Men over the age of 45 and women over the age of 55 should get cholesterol tests more often, as advancing age is a risk factor for high cholesterol. Talk with your provider to determine when you should get screened.

The National Heart, Lung, and Blood Institute recommends that children be screened once between the ages of 9–11, and once more between the ages of 17–21.

If you have a child with either a familial history of premature coronary disease or a history of obesity or diabetes, talk with your child’s pediatrician about whether more frequent cholesterol screening would be appropriate.