Blood tests can easily measure cholesterol levels. A blood test for cholesterol should include the entire lipoprotein profile: LDL, total cholesterol, HDL, and triglycerides. It is very difficult to measure LDL levels by themselves, but LDL levels can be reliably calculated using total cholesterol and HDL levels.
To obtain a reliable cholesterol reading, doctors advise:
- Avoid strenuous exercise for 24 hours before the test.
- Do not eat or drink anything but water for 12 hours beforehand.
- If the test results are abnormal, a second test should be performed between 1 week and 2 months after the first test.
Periodic cholesterol testing is recommended in all adults, but the major national guidelines differ on the age to start testing.
- Recommended starting ages are between 20 - 35 for men and 20 - 45 for women.
- Adults with normal cholesterol levels do not need to have the test repeated for 5 years unless changes occur in lifestyle (including weight gain and diet).
- Adults with a history of elevated cholesterol, diabetes, kidney problems, heart disease, and other conditions require more frequent testing.
Screening with a fasting lipid profile is recommended for children who:
- Have risk factors such as a family history of high cholesterol, and history of heart attacks before age 55 for men and before age 65 for women. Screening should begin as early as age 2 and no later than age 10.
- Are obese (above 85th percentile for weight) or who have diabetes. If the child’s cholesterol level tests normal, retesting is recommended in 3 - 5 years.
Patients already being treated for high cholesterol should be checked every 2 - 6 months.