What is a cholesterol test?
Cholesterol is a waxy, fat-like substance that’s found in your blood and every cell of your body. You need some cholesterol to keep your cells and organs healthy. Your liver makes all the cholesterol your body needs. But you can also get cholesterol from the foods you eat, especially meat, eggs, poultry, and dairy products. Foods that are high in dietary fat can also make your liver produce more cholesterol.
There are two main types of cholesterol: low-density lipoprotein (LDL), or “bad” cholesterol, and high-density lipoprotein (HDL), or “good” cholesterol. A cholesterol test is a blood test that measures the amount of each type of cholesterol and certain fats in your blood.
Too much LDL cholesterol in your blood may put you at risk for heart disease and other serious conditions. High LDL levels can cause the build-up of plaque, a fatty substance that narrows the arteries and blocks blood from flowing normally. When blood flow to the heart is blocked, it can cause a heart attack. When blood flow to the brain is blocked, it can lead to stroke and peripheral artery disease.
Other names for a cholesterol test: Lipid profile, Lipid panel
What is it used for?
If you have high cholesterol, you may not experience any symptoms at all, but you could be at significant risk for heart disease. A cholesterol test can give your health care provider important information about the cholesterol levels in your blood. The test measures:
- LDL levels. Also known as the “bad” cholesterol, LDL is the main source of blockages in the arteries.
- HDL levels. Considered the “good” cholesterol, HDL helps get rid of “bad” LDL cholesterol.
- Total cholesterol. The combined amount of low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol in your blood.
- Triglycerides A type of fat found in your blood. According to some studies, high levels of triglycerides may increase the risk of heart disease, especially in women.
- VLDL levels. Very low-density lipoprotein (VLDL) is another type of “bad” cholesterol. Development of plaque on the arteries has been linked to high VLDL levels. It’s not easy to measure VLDL, so most of the time these levels are estimated based on triglyceride measurements.
Why do I need a cholesterol test?
Your doctor may order a cholesterol test as part of a routine exam, or if you have a family history of heart disease or one or more of the following risk factors:
- High blood pressure
- Type 2 diabetes
- Excess weight or obesity
- Lack of physical activity
- A diet high in saturated fat
Your age may also be a factor, because your risk for heart disease increases as you get older.
What happens during a cholesterol test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Cholesterol tests are usually done in the morning, as you may be asked to refrain from eating for several hours prior to the test.
You may also be able to use an at-home kit to test for cholesterol. While instructions may vary between brands, your kit will include some kind of device to prick your finger. You’ll use this device to collect a drop of blood for testing. Be sure to follow the kit instructions carefully.
Also, be sure to tell your health care provider if your at-home test results shown your cholesterol level is higher than 200 mg/dl.
Will I need to do anything to prepare for the test?
You may need to fast (no food or drink) for 9 to 12 hours before your blood is drawn. Your health care provider will let you know if you need to fast and if there are any special instructions to follow.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
Cholesterol is usually measured in milligrams (mg) of cholesterol per deciliter (dL) of blood. The information below shows how the different types of cholesterol measurements are categorized.
|Total Cholesterol Level||Category|
|Less than 200mg/dL||Desirable|
|200-239 mg/dL||Borderline high|
|240mg/dL and above||High|
|LDL (Bad) Cholesterol Level||LDL Cholesterol Category|
|Less than 100mg/dL||Optimal|
|100-129mg/dL||Near optimal/above optimal|
|130-159 mg/dL||Borderline high|
|190 mg/dL and above||Very High|
|HDL (Good) Cholesterol Level||HDL Cholesterol Category|
|60 mg/dL and higher||Considered protective against heart disease|
|40-59 mg/dL||The higher, the better|
|Less than 40 mg/dL||A major risk factor for heart disease|
A healthy cholesterol range for you may depend on your age, family history, lifestyle, and other risk factors. In general, low LDL levels and high HDL cholesterol levels are good for heart health. High levels of triglycerides may also put you at risk for heart disease.
The LDL on your results may say “calculated” which means it includes a calculation of total cholesterol, HDL, and triglycerides. Your LDL level may also be measured “directly,” without using other measurements. Regardless, you want your LDL number to be low.
Is there anything else I need to know about my cholesterol levels?
High cholesterol can lead to heart disease, the number one cause of death in the United States. While some risk factors for cholesterol, such as age and heredity, are beyond your control, there are actions you can take to lower your LDL levels and reduce your risk, including:
- Eating a healthy diet. Reducing or avoiding foods high in saturated fat and cholesterol can help reduce the cholesterol levels in your blood.
- Losing weight. Being overweight can increase your cholesterol and risk for heart disease.
- Staying active. Regular exercise may help lower your LDL (bad) cholesterol levels and raise your HDL (good) cholesterol levels. It may also help you lose weight.
Talk to your health care provider before making any major change in your diet or exercise routine.