A doctor may recommend starting a fast the night before a cholesterol test, especially if you are taking statins. Some people may not need to fast.
Cholesterol is a fatty substance produced by your body and found in certain foods. Although your body needs some cholesterol to function properly, having too much or too high cholesterol increases your risk of heart attack or stroke.
Because of this risk, knowing your cholesterol levels is an important part of good heart health. The
People with known high cholesterol 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 not eat. But is fasting really necessary? The answer is maybe.
The truth is that your cholesterol can be tested without fasting. In the past, experts believed that fasting beforehand produces the most accurate results. This is because your low-density lipoprotein (LDL) levels — also known as “bad” cholesterol — can be affected by what you’ve eaten recently. Your levels of triglycerides (another type of fat in your blood) may also be affected by a recent meal.
New guidelines, published in the Journal of the American College of Cardiology, say people who don’t take statins may not need to fast before having their blood tested for cholesterol levels.
Your doctor may recommend fasting before having your cholesterol checked. If they tell you to fast, they will probably advise you not to eat 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 be hungry all day while you wait for your test.
Cholesterol is measured with a blood test. A healthcare provider will draw your blood with a needle and collect it in a vial. This usually takes place at your doctor’s office or lab where the blood is then analyzed.
The test only takes a few minutes and is relatively painless. However, you may have some pain or bruising on your arm around the injection site.
Your results will likely be available within a few days or within a few weeks.
If you are not already on cholesterol medication, fasting may not be necessary.
Depending on your situation, your doctor may recommend drinking only water and avoiding foods, other beverages, and certain medications to ensure your results are accurate.
What else should you avoid? Alcohol. Drinking within 24 hours before your test can affect your triglyceride levels.
Your blood will likely be checked using a test called a total lipid profile. To understand your cholesterol test results, you need to know the different types of cholesterol the test measures and what is considered normal, potentially risky, and high.
Here’s an overview of each type. Keep in mind that people with conditions like diabetes may need to aim for even lower numbers.
Total cholesterol
Your total cholesterol number is the total amount of cholesterol found in your blood.
- Acceptable: Under 200 mg/dL (milligrams per deciliter)
- border: 200 to 239 mg/dL
- High: 240 mg/dL or higher
Low Density Lipoprotein (LDL)
LDL is the cholesterol that blocks your arteries and increases your risk of heart disease.
- Acceptable: Under 70 if coronary artery disease is present
- Below 100 mg/dL if you are at risk for coronary artery disease or have a history of diabetes
- border: 130 to 159 mg/dL
- High: 160 mg/dL or higher
- Very high: 190 mg/dL and above
High Density Lipoprotein (HDL)
Also called good cholesterol, HDL helps protect you against heart disease. This type removes excess cholesterol from your blood and helps 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 less for men and 49 mg/dL or less for women
- Ideal: 60 mg/dL or higher
Triglycerides
High triglyceride levels combined with high LDL levels increase the risk of heart disease.
- Acceptable: 149 mg/dL or lower
- border: 150 to 199 mg/dL
- High: 200 mg/dL or higher
- Very high: 500 mg/dL and above
You want your cholesterol test results to fall within acceptable ranges. If your numbers are in the borderline or high range, you’ll need to make some lifestyle changes and you may need to take medications like a statin. Your doctor may want to check your values more often.
Getting your cholesterol tested is an important part of keeping your heart and blood vessels healthy. In general, fasting is not required for your test. But your doctor may recommend fasting if you’re already taking cholesterol medications.
Before your test, be sure to ask your doctor if you need to fast.