Cholesterol is a fatty material that’s produced by your body and found in certain foods. While your body needs some cholesterol in order to function properly, having too much, or high cholesterol, raises your risk of a heart attack or stroke.
Because of this risk, knowing your cholesterol levels is an important part of good heart health. The American Heart Association (AHA) recommends that adults have a cholesterol test every four to six years, starting at age 20. People with known high cholesterol levels or other chronic health conditions should get tested more often.
To prepare for a cholesterol test, you may have heard that you should fast, or avoid eating. But is fasting really necessary? The answer is: maybe.
Should you fast before your cholesterol test?
The truth is, your cholesterol can be tested without fasting. However, experts agree that fasting ahead of time produces the most accurate results. This is because your low-density lipoproteins (LDL) — also known as “bad” cholesterol — may be affected by what you’ve recently eaten. Your levels of triglycerides (another type of fat in your blood) may also be affected by a recent meal.
But you don’t need to decide whether or not to fast; your doctor will tell you if you need to. If they say you should fast, they’ll likely suggest that you avoid eating for 9 to 12 hours before your test.
For this reason, cholesterol tests are often scheduled in the morning. That way, you don’t have to spend a whole day hungry while waiting to have your test.
How is cholesterol tested?
Cholesterol is measured using a blood test. A healthcare provider will draw your blood using a needle and collect it in a vial. This typically takes place at your doctor’s office or at a lab where the blood is then analyzed.
The test only takes a couple of minutes and is relatively painless. However, you might have some soreness or bruising on your arm around the injection site.
Your results will likely be available in a few days or within a couple of weeks.
How should I prepare for my cholesterol test?
According to the AHA, doctors recommend drinking only water and avoiding food, other drinks, and certain medications in order to make sure your results are accurate.
What else should you avoid? Alcohol. Drinking within 24 hours before your test can affect your triglyceride levels.
How to read your results
Your blood will likely be checked using a test called a total lipid profile. To understand your cholesterol test results, you’ll need to know the different types of cholesterol that the test measures and what’s considered normal, potentially risky, and high.
Here’s a breakdown of each type. Keep in mind that people who have conditions such as diabetes may need to aim for even lower numbers.
Your total cholesterol number is the overall amount of cholesterol found in your blood.
- Acceptable: 200 mg/dL (milligrams per deciliter) or lower
- Borderline: 200 to 239 mg/dL
- High: 240 mg/dL or higher
Low-density lipoprotein (LDL)
LDL is the cholesterol that blocks your blood vessels and increases your risk of heart disease.
- Acceptable: 100 mg/dL or lower
- Borderline: 130 to 159 mg/dL
- High: 160 mg/dL or higher
High-density lipoprotein (HDL)
HDL is also called “good cholesterol” and helps protect you from heart disease. This type removes excess cholesterol from your blood, helping to prevent buildup. The higher your HDL levels are, the better.
- Acceptable: 40 mg/dL or higher for men and 50 mg/dL or higher for women
- Low: 39 mg/dL or lower
- Ideal: 60 mg/dL or higher
High triglyceride levels coupled with high levels of LDL raise your risk for heart disease.
- Acceptable: 149 mg/dL or lower
- Borderline: 150 to 199 mg/dL
- High: 200 mg/dL or higher
You want your cholesterol test results to fall within the acceptable ranges. If your numbers are in the borderline or high levels, you’ll need to make some lifestyle changes and may need to take medication such as a statin. Your doctor may also want to check your levels more often. Your doctor can create a treatment plan that’s right for your needs.
Getting your cholesterol levels tested is an important part of keeping your heart and blood vessels healthy. Fasting before your test may help you get the most accurate results. However, your doctor may not feel that fasting is necessary. Be sure to ask your doctor before your test if fasting is needed.