We need a certain amount of cholesterol for organ functions. All the cholesterol we need is produced in the liver. We also eat foods rich in cholesterol. Furthermore, eating fatty foods stimulates the liver to 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 measures the amount of each type of cholesterol and certain other lipids in the blood.

Too high a level of LDL cholesterol in your blood can put you at risk for heart disease. heart disease and other serious health problems. High LDL levels can cause plaque to form, a fatty substance that narrows arteries and blocks normal blood flow. When blood flow to the heart is blocked, it can lead to heart attack (myocardial infarction), and when blood flow to the brain is obstructed, a stroke (cerebral infarction or stroke) and peripheral arterial disease.

Other names for cholesterol test: lipid profile, lipid panel

What is it used for and what tests are performed?

If you have high cholesterol, you may not experience any symptoms, but you could be at significant risk for heart disease. A cholesterol test gives your doctor or healthcare professional important information about your blood cholesterol levels. The test measures:

• LDL levels: LDL, also known as "bad" cholesterol, is the main cause of blockages in the arteries
• HDL levels: HDL, considered the "good" cholesterol, helps eliminate "bad" cholesterol or LDL
• Total cholesterol: The total amount of low-density lipoproteins (LDL cholesterol) and high-density lipoproteins (HDL cholesterol) in the blood
• Triglycerides: A type of lipid or fat found in the body. According to some studies, high triglyceride levels may increase the risk of heart disease, especially in women.
• VLDL levels: Very low-density lipoproteins (VLDL) are another type of "bad" cholesterol. A link has been found between high VLDL levels and plaque formation in the arteries. VLDL is not easy to measure. Therefore, these levels are often calculated based on triglyceride levels.

Why do I need a cholesterol test?

Your doctor may order a cholesterol test as part of a routine checkup, or if you have a family history of heart disease or one or more of the following risk factors:

• High blood pressure (high blood pressure)
• Type 2 diabetes
• Smoke
• Overweight or obesity
• Lack of physical activity
• A diet rich in saturated fats

Your age could also be a factor because the risk of heart disease increases with age.

What happens during a cholesterol test?

A healthcare professional will take a blood sample from a vein in your arm using a small needle. After inserting the needle, a small amount of blood is withdrawn and placed in a test tube. You may experience mild discomfort when the needle is inserted or removed. This process usually takes less than five minutes.

Cholesterol tests are usually done in the morning, and you are usually asked not to eat anything for several hours beforehand.

Should I do anything to prepare for the test?

Do not eat or drink anything except water for 9 to 12 hours before the blood draw. Unless you have a medical condition that prevents you from doing this fast.

Does this test have any risks?

The risks of a blood test are minimal. You may experience mild pain or bruising where the needle is inserted, but most symptoms disappear quickly.

What do the results mean?

Cholesterol is usually measured in milligrams (mg) of cholesterol per deciliter (dl)

The healthy cholesterol range for you depends on your age, family history, lifestyle, and other risk factors. In general, low LDL cholesterol levels and high HDL cholesterol levels are good for heart health. High triglyceride levels also put you at risk for heart disease.

Your LDL results may say "calculated." This means they include a calculation of total cholesterol, HDL cholesterol, and triglycerides. Your LDL level may also be measured "directly," without any other measurements. In either case, a low LDL value is desirable.

Learn more about medical tests, reference ranges, and how to understand the results.

Is there anything else I need to know about cholesterol levels?

High cholesterol can cause heart disease, the leading cause of death in the United States. Although some cholesterol risk factors cannot be controlled, such as age or genetics, there are things you can do to reduce your LDL levels and risk, such as:

• Follow a healthy diet: Reducing or avoiding foods high in saturated fat and cholesterol helps lower blood cholesterol levels.
• Lose weight: Being overweight can increase your cholesterol levels and your risk of heart disease.
• Stay active: Exercising regularly helps lower your LDL (bad) cholesterol levels and increases your HDL (good) cholesterol levels. It also helps you lose weight.

Talk to your doctor or healthcare professional before making any major changes to your diet or exercise routine.