Cholesterol

Total blood cholesterol, serum cholesterol; lipid panel; lipid profile

This test measures the amount of cholesterol in your blood. This helps your healthcare provider figure out your risk for heart disease.

Cholesterol is a waxy fat-like substance found in all of your body's cells. It plays an important role in various body processes. But your body can have too much cholesterol if you eat the wrong types of foods. These include fried foods and foods with saturated or trans fats. Some health conditions can also make your cholesterol level too high.

If you have too much cholesterol in your blood, it can stick to the walls of the arteries in your heart (coronary arteries). The extra cholesterol can make your blood vessels narrower (atherosclerosis). This narrowing makes it harder to get enough blood through your blood vessels. If your heart muscles don't get enough blood, this can cause chest pain and heart attack. Cholesterol can also stick to the walls of arteries elsewhere in your body (such as the brain, and legs). This can cause other types of artery diseases. 

The American Heart Association advises all adults ages 20 and older have their cholesterol and other traditional risk factors checked every 4 to 6 years.  You may need to have your blood tested more often if you are at risk for heart disease or stroke. Work with your healthcare provider to find out your risk for cardiovascular disease and stroke.

You may have this test as part of your regular health checkup. You may have this test done more often if you are at risk for heart disease or have other health problems caused by high cholesterol.

Here are some common reasons for the test:

• You have risk factors for heart disease. These include older age, obesity, family history of heart disease, high blood pressure, smoking, and diabetes.

• You have a condition that may be closely linked to high cholesterol. This includes diabetes, alcoholism, and thyroid, liver, or kidney disease.

• You eat a diet high in cholesterol and fats.

You may also have this test if you had high or borderline cholesterol on an earlier blood test. Your healthcare provider may want to check to see whether medicine, diet, exercise, and other lifestyle changes are helping lower your cholesterol.

You may need other blood tests to find out your HDL (good) cholesterol, LDL (bad) cholesterol, and triglyceride levels. This combination of blood tests is called a lipoprotein profile or a lipid profile.

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

Total cholesterol is measured in milligrams per deciliter (mg/dL). This is what your number may mean:

• Less than 200 mg/dL is desirable.

• 200 mg/dL to 239 mg/dL is borderline high.

• 240 mg/dL or higher means your cholesterol is high.

High cholesterol is only one of the big risk factors for heart disease and stroke. Other things that can increase your risk, include smoking, diabetes, lack of exercise, high blood pressure, unhealthy diet, and age.

To help find your overall risk, your healthcare provider may use a risk calculator. It takes into account your cholesterol level and other risk factors. Ask your healthcare provider about your 10-year risk if you are older than 40 or your lifetime risk if you are age 20 to 39. Depending on all of your risk factors, your healthcare provider will talk with you about your cholesterol results and what is important for overall health.

High cholesterol may be linked to these conditions:

• Inherited diseases that cause high cholesterol

• Gallbladder stones

• Kidney failure

• Cancer of the pancreas or prostate

• Low thyroid hormone

• Diabetes

• Obesity

Cholesterol levels below 140 mg/dL may happen with:

• Very healthy lifestyle and diet

• Severe liver disease

• High thyroid hormone

• Severe burns

• White blood cell cancers

• Poor nutrition

• Some types of anemia

• Short-term illness or infection

• Chronic lung disease

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

Your diet, age, alcohol use, and other lifestyle choices may affect your results. Many medicines may also affect your results. Pregnancy may also affect your results. Having a heart attack in the last 3 months will also affect your results.

You may be asked to eat your regular diet and not drink alcohol for at least 2 days before this test. You may be asked not to eat or drink anything but water for a certain amount of time before the test (fast or fasting).

Tell your healthcare provider about all medicines, herbs, vitamins, and supplements you take. This includes medicines that don't need a prescription and any illegal drugs you may use.