Cholesterol

Cholesterol is a soft, waxy substance found in all parts of the body. Your body makes some cholesterol, and some cholesterol comes from the food you eat.
Your body needs a little bit of cholesterol to work properly. But too much cholesterol can clog your arteries and lead to heart disease. This article focuses on cholesterol and your diet.

See also:

HDL test ("good" cholesterol)
HDL stands for high density lipoprotein, a form of "good" cholesterol. Lipoproteins are proteins in the blood that move cholesterol, triglycerides, and other fats, called lipids, to various parts of the body.
This article discusses the blood test used to measure levels of HDL cholesterol in your blood

Alternative Names
High-density lipoprotein test

How the Test Is Performed
A blood sample is needed.

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

How to Prepare for the Test
Do not eat anything for 9 - 12 hours before the test.

How the Test Will Feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test Is Performed
This test is done to check the level of cholesterol in your blood and to see if you are at high risk fo a heart attack, stroke, or other cardiovascular problem. Studies of both men and women have shown that the higher your HDL, the lower your risk of coronary artery disease. This is why HDL is sometimes referred to as "good" cholesterol.

The main function of HDL is to help soak up excess cholesterol from the walls of blood vessels and carry it to the liver, where it breaks down and is removed from the body in the bile.

The laboratory test for HDL actually measures how much cholesterol is in the HDL, not the actual amount of HDL in the blood.

Normal Results
In general, your risk for heart disease, including a heart attack, increases if your HDL cholesterol level is less than 40 mg/dL.

Men are at particular risk if their HDL is below 37 mg/dL.

Women are at particular risk if their HDL if their HDL is below 47 mg/dL.

An HDL 60 mg/dL or above helps protect against heart disease.

Women tend to have higher HDL cholesterol than men.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean
Low HDL levels may indicate an increased risk of atherosclerotic heart disease.

They also may be associated with:

Familial combined hyperlipidemia
Noninsulin-dependent diabetes (NIDD)

Risks
Risks associated with this test may include:

Excessive bleeding
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Multiple punctures to locate veins

Considerations
HDL will usually be done as part of an overall lipid profile, where "bad" cholesterol (LDL) and triglycerides will also be measured. The combined information gathered from all of these tests may help your risk of heart attack, stroke, and peripheral vascular disease.

Your health care provider will recommend therapy if your risk is found to be high. Regular exercise can increase HDL levels by several points.

LDL test ("bad" cholesterol)
The LDL test measures how much low-density lipoprotein (LDL) you have in your blood. LDL is a type of cholesterol. Too much LDL in the blood can clog arteries.

Alternative Names
Low-density lipoprotein test

How the Test Is Performed
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to Prepare for the Test
You may be told not to eat or drink anything for 9 - 12 hours before the test.

The health care provider may tell you to stop taking certain drugs before the procedure. Drugs that can affect the LDL test include aspirin, birth control pills, phenothiazines, corticosteroids, and sulfonamides.

How the Test Will Feel
When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test Is Performed
This test is usually done to determine your risk for heart disease. The LDL test is usually done as part of a lipid analysis, which also checks for total cholesterol, HDL, and triglycerides.

LDL is carries cholesterol to various tissues throughout the body. Too much LDL, commonly called "bad cholesterol," can lead to cardiovascular disease.

According to the National Heart, Lung, and Blood Institute, the lower your LDL, the lower your risk for heart disease or stroke.

What Abnormal Results Mean
High levels of LDL may be associated with:

Increased risk of atherosclerotic heart disease
Familial hyperlipoproteinemia
Lower-than-normal levels of LDL may be caused by:
Malabsorption (inadequate absorption of nutrients from the intestinal tract)
Malnutrition
Additional conditions under which the test may be performed:
Familial combined hyperlipidemia
Familial dysbetalipoproteinemia
Familial hypertriglyceridemia

Risks
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

Excessive bleeding
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)

Lipid profile
A coronary risk profile involves a battery of blood tests to evaluate cholesterol and triglycerides. These are indicators of risk for heart disease.

Alternative Names
Lipoprotein/cholesterol analysis; Lipid profile

How the Test Is Performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to cause the vein to swell with blood.

A needle is inserted into the vein, and the blood is collected in an airtight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed and the puncture site is covered with gauze or with a bandage to stop any bleeding.

In infants or young children, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

The blood is analyzed by the laboratory to determine the levels of:

Triglycerides
LDL (low density lipoprotein) cholesterol
HDL (high density lipoprotein) cholesterol
Total cholesterol
Serum VLDL (very low density lipoprotein) cholesterol

How to Prepare for the Test
You should not eat or drink anything except water for 9-12 hours before having your blood drawn.

How the Test Will Feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test Is Performed
The coronary risk profile is most often performed:

As a screening examination to determine the general health of the person
When there is a history of heart disorders or other disorders related to atherosclerosis
To determine the effect of diet and medications to control hypercholesterolemia

Normal Results
Triglycerides: 10 to 150 mg/dL
LDL cholesterol: 60 to 130 mg/dL
HDL cholesterol: greater than 40 mg/dL
Total cholesterol: less than 200 mg/dL
VLDL: 2 to 38 mg/dL
Note: mg/dL = milligrams per deciliter

The ideal values for patients with known coronary artery disease are different from those for patients without coronary disease. High values of HDL (60 or higher) are protective and are therefore desirable.

Additional blood tests, such as C-reactive protein (CRP), may be added to the profile in some laboratories.

What Abnormal Results Mean
Elevated values indicate an increased risk for atherosclerosis and related disorders, including heart disease.

Risks
There is very little risk for having your blood drawn. However, veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Excessive bleeding
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Multiple punctures to locate veins
Back to TopConsiderations
Conditions under which the test may be performed:

Acute MI
Atheroembolic renal disease
Familial hyperlipidemia
Familial hypertriglyceridemia
Familial hypercholesterolemia
Hyperlipidemia
Ischemic cardiomyopathy
Stroke secondary to atherosclerosis
Transient ischemic attack (TIA)

High blood cholesterol and triglycerides
The medical term for high blood cholesterol and triglycerides is lipid disorder. Such a disorder occurs when you have too many fatty substances in your blood. These substances include cholesterol and triglycerides.
A lipid disorder increases your risk for atherosclerosis and heart disease.

Alternative Names
Lipid disorders; Hyperlipoproteinemia; Hyperlipidemia; Dyslipidemia; Hypercholesterolemia

Causes
High cholesterol and other lipid disorders can be inherited (passed down through families) or associated with:

Fatty diets
Disease such as diabetes, hypothyroidism, Cushing syndrome, and kidney failure
Certain medications, including birth control pills, estrogen, corticosteroids, certain diuretics, and beta-blockers
Lifestyle factors, including inactivity and regular, excessive alcohol use
If you smoke and also have high cholesterol you have an even greater risk for heart disease.

Lipid disorders are more common in men than women.

Exams and Tests »
Tests to diagnose a lipid disorder may include:

Lipoprotein test
Lipoprotein(a) analysis
HDL test
LDL test

Treatment »
How you are treated depends on your age, health history, if you smoke, and other risk factors for heart disease, such as:

Diabetes
Poorly controlled high blood pressure
Family history of heart disease
There are steps that everyone can take to improve their cholesterol levels, and help prevent heart disease and heart attack. Here are the most important ones:

Choose foods low in saturated fat.
Exercise regularly.
Lose weight if you are overweight.
Get routine health checkups and cholesterol screenings.
If lifestyle changes do not help or your cholesterol level remains very high, your doctor may may recommend medication. There are several types of drugs available to help lower blood cholesterol levels, and they work in different ways. Some are better at lowering LDL cholesterol, some are good at lowering triglycerides, while others help raise HDL cholesterol.

The most commonly used drugs for treating high LDL cholesterol are called statins. Other drugs that may be used include bile acid sequestering resins, cholesterol absorption inhibitors, fibrates, and nicotinic acid (niacin).

Outlook (Prognosis)
If you are diagnosed with high cholesterol, you will probably need to continue lifestyle changes and drug treatment throughout your life. Periodic monitoring of your cholesterol blood levels is necessary. Reducing high cholesterol levels will slow the progression of atherosclerosis.

Possible Complications
Possible complications of high cholesterol include:

Atherosclerosis
Coronary artery disease
Stroke
Heart attack or death

When to Contact a Medical Professional
Have your cholesterol checked every 5 years or so, starting between the ages of 20 and 30. If you have high cholesterol or other risk factors for heart disease, make appointments as recommended by your doctor.

Prevention
To help prevent high cholesterol:

Keep a healthy body weight
Eat a well-balanced, low-fat diet

Alternative Names
Diet - cholesterol

Function
Cholesterol helps the body produce hormones, bile acid, and vitamin D. Cholesterol moves through the bloodstream to be used by all parts of the body.

Food Sources
Cholesterol is found in eggs, dairy products, meat, and poultry. Egg yolks and organ meats (liver, kidney, sweetbread, and brain) are high in cholesterol. Fish generally contains less cholesterol than other meats, but some shellfish are high in cholesterol.

Foods of plant origin (vegetables, fruits, grains, cereals, nuts, and seeds) contain no cholesterol.

Fat content is not a good measure of cholesterol content. For example, liver and other organ meats are low in fat, but very high in cholesterol.

Side Effects
In general, your risk of developing heart disease or atherosclerosis goes up as your level of blood cholesterol increases.

Recommendations
More than half of the adult population has blood cholesterol levels higher than the desirable range. High cholesterol levels often begin in childhood. Some children may be at higher risk due to a family history of high cholesterol.

To lower high cholesterol levels:

Limit total fat intake to 25 - 35% of total daily calories. Less than 7% of daily calories should be from saturated fat, no more than 10% should be from polyunsaturated fat, and no more than 20% from monounsaturated fat.
Eat less than 200 mg of dietary cholesterol per day.
Get more fiber in your diet.
Lose weight.
Increase physical activity.

The recommendations for children's diets are similar to those of adults. It is very important that children get enough calories to support their growth and activity level, and that the child achieve and maintain a desirable body weight

The following two sample menus provide examples of an average American diet and a low-fat diet.

AVERAGE AMERICAN DIET

Breakfast
1 egg scrambled in 1 teaspoon of butter
2 slices of white toast
1 teaspoon of butter
1/2 cup of apple juice
Snack
1 cake donut
Lunch
1 ham and cheese sandwich (2 ounces of meat, 1 ounce of cheese)
White bread
1 teaspoon of mayonnaise
1-ounce bag potato chips
12-ounce soft drink
2 chocolate chip cookies
Snack
8 wheat thins
Dinner
3 ounces of broiled sirloin
1 medium baked potato
1 tablespoon of sour cream
1 teaspoon of butter
1/2 cup of peas, 1/2 teaspoon of butter
Totals: 2,000 Calories, 84 grams fat, 34 grams saturated fat, 425 milligrams cholesterol. The diet is 38% total fat, 15% saturated fat.

LOW FAT DIET

For the same number of calories, a low-fat diet provides 190 mg of cholesterol, compared to 510 mg of cholesterol for an average American diet. Because fat is high in calories, the low-fat diet actually has more food than the typical American diet. An example follows:

Breakfast
1 cup of toasted oat ring cereal
1 cup of skim milk
1 slice of whole-wheat bread
1 banana
Snack
1 cinnamon raisin bagel, 1/2 ounce light cream cheese
Lunch
Turkey sandwich (3 ounces of turkey) on rye bread with lettuce
1 orange
3 Fig Newton cookies
1 cup skim milk
Snack
Nonfat yogurt with fruit
Dinner
3 ounces of broiled chicken breast
1 medium baked potato
1 tablespoon of nonfat yogurt
1/2 cup of broccoli
1 dinner roll
1 cup skim milk
Totals: 2,000 Calories, 38g fat, 9.5g saturated fat, 91mg cholesterol. The diet is 17% fat, 4% saturated fat.

NOTE: The low-fat diet example is too low in fat for small children to promote good growth. In addition, it may be difficult for them to eat such a large volume of food. Children should have a diet that is closer to 30% of calories from fat. Lower-fat diets may be appropriate in some children. Ask your doctor what is best for your child.