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
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.
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 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.
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.
|Desirable||Less than 200mg/dL|
|Borderline high||200-239 mg/dL|
|High||240mg/dL and above|
|Optimal||Less than 100mg/dL|
|Near optimal/above optimal||100-129mg/dL|
|Borderline high||130-159 mg/dL|
|Very High||190 mg/dL and above|
|Considered protective against heart disease||60 mg/dL and higher|
|The higher, the better||40-59 mg/dL|
|A major risk factor for heart disease||Less than 40 mg/dL|
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.