What Is Cholesterol?
To understand high blood cholesterol
(ko-LES-ter-ol), it is important to know more about cholesterol.
- Cholesterol is a waxy, fat-like substance that
is found in all cells of the body. Your body needs some cholesterol to work the
right way. Your body makes all the cholesterol it needs.
- Cholesterol is also found in some of the foods
you eat.
- Your body uses cholesterol to make hormones,
vitamin D, and substances that help you digest foods.
Blood is watery, and cholesterol is fatty. Just like
oil and water, the two do not mix. To travel in the bloodstream, cholesterol is
carried in small packages called lipoproteins (lip-o-PRO-teens). The small
packages are made of fat (lipid) on the inside and proteins on the outside. Two
kinds of lipoproteins carry cholesterol throughout your body. It is important
to have healthy levels of both:
- Low-density lipoprotein (LDL) cholesterol is
sometimes called bad cholesterol.
- High LDL cholesterol leads to a buildup of
cholesterol in arteries. The higher the LDL level in your blood, the greater
chance you have of getting heart disease.
- High-density lipoprotein (HDL) cholesterol is
sometimes called good cholesterol.
- HDL carries cholesterol from other parts of
your body back to your liver. The liver removes the cholesterol from your body.
The higher your HDL cholesterol level, the lower your chance of getting heart
disease.
What Is High Blood Cholesterol?
Too much cholesterol in the blood, or high blood
cholesterol, can be serious. People with high blood cholesterol have a greater
chance of getting heart disease. High blood cholesterol on its own does not
cause symptoms, so many people are unaware that their cholesterol level is too
high.
Cholesterol can build up in the walls of your
arteries (blood vessels that carry blood from the heart to other parts of the
body). This buildup of cholesterol is called plaque (plak). Over time, plaque
can cause narrowing of the arteries. This is called
atherosclerosis
(ath-er-o-skler-O-sis), or hardening of the arteries.
The illustration shows a normal
artery with normal blood flow (figure A) and an artery containing plaque
buildup (figure B).
Special arteries, called coronary arteries, bring
blood to the heart. Narrowing of your coronary arteries due to plaque can stop
or slow down the flow of blood to your heart. When the arteries narrow, the
amount of oxygen-rich blood is decreased. This is called
coronary
heart disease (CHD). Large plaque areas can lead to chest pain called
angina
(an-JI-nuh or AN-juh-nuh). Angina happens when the heart does not receive
enough oxygen-rich blood. Angina is a common symptom of CHD.
Some plaques have a thin covering and can burst
(rupture), releasing cholesterol and fat into the bloodstream. The release of
cholesterol and fat may cause your blood to clot. A clot can block the flow of
blood. This blockage can cause angina or a
heart
attack.
Lowering your cholesterol level decreases your
chance for having a plaque burst and cause a heart attack. Lowering cholesterol
may also slow down, reduce, or even stop plaque from building up.
Plaque and resulting health problems can also occur
in arteries elsewhere in the body.
Other Names for High Blood Cholesterol
- Hypercholesterolemia
(HI-per-ko-LES-ter-ol-E-me-a)
- Hyperlipidemia (HI-per-lip-i-DE-me-a)
What Causes High Blood Cholesterol?
A variety of things can affect the cholesterol
levels in your blood. Some of these things you can control and others you
cannot.
You can control:
- What you eat. Certain foods have types of fat
that raise your cholesterol level.
- Saturated fat raises your low-density
lipoprotein (LDL) cholesterol level more than anything else in your diet.
- Trans fatty acids (trans
fats) are made when vegetable oil is hydrogenated to harden it. Trans
fatty acids also raise cholesterol levels.
- Cholesterol is found in foods that come from
animal sources, for example, egg yolks, meat, and cheese.
- Your weight. Being
overweight
tends to increase your LDL level, lower your high-density lipoprotein (HDL)
level, and increase your total cholesterol level.
- Your activity. Lack of regular exercise can lead
to weight gain, which could raise your LDL cholesterol level. Regular exercise
can help you lose weight and lower your LDL level. It can also help you raise
your HDL level.
You cannot control:
- Heredity. High blood cholesterol can run in
families. An inherited genetic condition (familial hypercholesterolemia) results in very high LDL
cholesterol levels. It begins at birth, and may result in a
heart
attack at an early age.
- Age and sex. Starting at puberty, men have lower
levels of HDL than women. As women and men get older, their LDL cholesterol
levels rise. Younger women have lower LDL cholesterol levels than men, but
after age 55, women have higher levels than men.
What Are the Signs and Symptoms of High Blood
Cholesterol?
There are usually no signs or symptoms of high blood
cholesterol. Many people don't know that their cholesterol level is too high.
Everyone age 20 and older should have their
cholesterol levels checked at least once every 5 years. You and your doctor can
discuss how often you should be tested.
How Is High Blood Cholesterol Diagnosed?
High blood cholesterol is diagnosed by checking
levels of cholesterol in your blood. It is best to have a blood test called a
lipoprotein profile to measure your cholesterol levels. You will need to not
eat or drink anything (fast) for 9 to 12 hours before taking the test.
The lipoprotein profile will give information about
your:
- Total cholesterol
- Low-density lipoprotein (LDL) bad cholesterol:
the main source of cholesterol buildup and blockage in the arteries
- High-density lipoprotein (HDL) good cholesterol:
the good cholesterol that helps keep cholesterol from building up in arteries
- Triglycerides: another form of fat in your blood
If it is not possible to get a lipoprotein profile
done, knowing your total cholesterol and HDL cholesterol can give you a general
idea about your cholesterol levels. Testing for total and HDL cholesterol does
not require fasting. If your total cholesterol is 200 mg/dL or more, or if your
HDL is less than 40 mg/dL, you will need to have a lipoprotein profile done.
Cholesterol levels are measured in milligrams (mg)
of cholesterol per deciliter (dL) of blood. See how your cholesterol numbers
compare to the tables below.
Total Cholesterol Level |
Total Cholesterol Category |
Less than 200 mg/dL |
Desirable |
200239 mg/dL |
Borderline high |
240 mg/dL and above |
High |
LDL Cholesterol Level |
LDL Cholesterol Category |
Less than 100 mg/dL |
Optimal |
100129 mg/dL |
Near optimal/above optimal |
130159 mg/dL |
Borderline high |
160189 mg/dL |
High |
190 mg/dL and above |
Very high |
HDL Cholesterol Level |
HDL Cholesterol Category |
Less than 40 mg/dL |
A major risk factor for heart disease |
4059 mg/dL |
The higher, the better |
60 mg/dL and above |
Considered protective against heart disease |
Triglycerides can also raise your risk for heart
disease. If you have levels that are borderline high (150199 mg/dL)
or high (200 mg/dL or more), you may need treatment. Things that can increase
triglyceride levels include:
- Overweight
- Physical inactivity
- Cigarette smoking
- Excessive alcohol use
- Very high carbohydrate diet
- Certain diseases and drugs
- Genetic disorders
How Is High Blood Cholesterol Treated?
The main goal of cholesterol-lowering treatment is
to lower your low-density lipoprotein (LDL) level enough to reduce your risk
for having a
heart
attack or diseases caused by hardening of the arteries. In general, the
higher your LDL level and the more risk factors you have, the greater your
chances of developing heart disease or having a heart attack. (A risk factor is
a condition that increases your chance of getting a disease.)
Some people are at high risk for heart attack
because they already have heart disease. Other people are at high risk for
developing heart disease because they have diabetes or a combination of risk
factors for heart disease. Follow the steps below to find out your risk for
getting heart disease. Talk with your doctor about lowering your risk.
Check the list to see how many of the risk factors
you have. These are the risk factors that affect your LDL goal:
- Cigarette smoking
-
High
blood pressure (140/90 mg/dL or higher), or if you are on blood pressure
medicine
- Low high-density lipoprotein (HDL) cholesterol
(less than 40 mg/dL)1
- Family history of early heart disease (heart
disease in father or brother before age 55; heart disease in mother or sister
before age 65)
- Age (men 45 years or older; women 55 years or
older)
If you have two or more of the risk factors in the
list above, use the
NHLBI
10-Year Risk Calculator to find your risk score. Risk scores refer to the
chance of having a heart attack in the next 10 years, given as a percentage.
Use your medical history, number of risk factors,
and risk score to find your risk for developing heart disease or having a heart
attack according to the table below.
If You Have |
You Are in Category |
And Your LDL Goal Is |
Heart disease, diabetes, or a risk score higher than
20% |
I. High risk |
Less than 100 mg/dL* |
Two or more risk factors and a risk score
1020% |
II. Moderately high risk |
Less than 130 mg/dL |
Two or more risk factors and a risk score lower
than 10% |
III. Moderate risk |
Less than 130 mg/dL |
One or no risk factors |
IV. Low
to moderate risk |
Less
than 160 mg/dL |
*Some
people in this category are at very high risk because they have just had a
heart attack or because they have a combination of heart disease together with
diabetes, risk factors that are severe, or
metabolic
syndrome. If you are at very high risk, your doctor may set your LDL goal
even lower, to less than 70 mg/dL. Your doctor may also set the LDL goal at
this lower level if you have heart disease alone.
After following the above steps, you should have an
idea about your risk for getting heart disease or having a heart attack. There
are two main ways to lower your cholesterol in order to lower your risk:
-
Therapeutic
Lifestyle Changes (TLC)includes a cholesterol-lowering diet (called
the TLC Diet), physical activity, and weight management. TLC is for anyone
whose LDL is above goal.
- Drug Treatmentif cholesterol-lowering
drugs are needed, they are used together with TLC treatment to help lower your
LDL.
Your doctor will set your LDL goal. The higher your
risk for heart disease, the lower your LDL goal will be. Using the following
guide, you and your doctor can develop a possible plan for treating your high
blood cholesterol.
Category I, high risk, your LDL goal is less than
100 mg/dL.*
Your LDL Level |
Treatment |
If your LDL is 100 or above |
You will need to begin the
TLC
Diet together with drug treatment. |
Even if your LDL is below 100 |
You
should follow the TLC Diet on your own to keep your LDL as low as
possible. |
* Your LDL goal may be set even
lower, to less than 70 mg/dL, if you are at very high
risk or if you have heart disease. If you have this lower goal and your LDL
is 70 mg/dL or higher, you will need to begin the TLC Diet together with drug
treatment.
Category II, moderately high risk, your LDL goal is
less than 130 mg/dL.
Your LDL Level |
Treatment |
If your LDL is 130 mg/dL or above |
You will need to begin the
TLC
Diet. |
If your LDL is 130 mg/dL or more after 3 months on the
TLC Diet |
You may need drug treatment along with the TLC Diet. |
If your LDL is less than 130 mg/dL |
You
will need to follow the
Heart
Healthy Diet. |
Category III, moderate risk, your LDL goal is less
than 130 mg/dL.
Your LDL Level |
Treatment |
If your LDL is 130 mg/dL or above |
You will need to begin treatment with the
TLC
Diet. |
If your LDL is 160 mg/dL or more after you have tried
the TLC Diet for 3 months |
You may need drug treatment along with the TLC Diet. |
If your LDL is less than 130 mg/dL |
You
will need to follow the
Heart
Healthy Diet. |
Category IV, low to moderate risk, your LDL goal is
less than 160 mg/dL.
Your LDL Level |
Treatment |
If your LDL is 160 mg/dL or above |
You will need to begin the
TLC
Diet. |
If your LDL is still 160 mg/dL or more after 3 months
on the TLC Diet |
You may need drug treatment along with the TLC Diet. |
If your LDL is less than 160 mg/dL |
You
will need to follow the
Heart
Healthy Diet. |
Lowering Cholesterol With TLC
TLC is a set of lifestyle changes you can make to
help lower your LDL cholesterol. The main parts of TLC are:
- The TLC Diet, which recommends:
- Limiting the amount of saturated fat,
trans fat, and cholesterol you eat.
- Eating only enough calories to achieve or
maintain a healthy weight.
- Increasing the soluble fiber in your diet.
For example, oatmeal, kidney beans, and apples are good sources of soluble
fiber.
- Adding cholesterol-lowering foods, such as
margarines that contain
plant sterol or stanol esters that can help lower cholesterol.
- Weight management:
- Losing weight if you are overweight can help
lower LDL. Weight management is especially important for those with a group of
risk factors that includes raised triglyceride and/or reduced HDL levels and
being overweight with a large waist measurement (40 inches or more for men and
35 inches or more for women). This is called
metabolic
syndrome and it raises your risk for getting heart disease.
- Physical activity:
- Regular
physical
activity is recommended for everyone. It can help raise HDL levels and
lower LDL levels, and is especially important for those with raised
triglyceride and/or reduced HDL levels who are overweight with a large waist
measurement. Aim for at least 30 minutes of moderate-intensity activity, such
as brisk walking, on most, and preferably all, days of the week.
Cholesterol-Lowering Medicines
Along with suggesting that you change the way you
eat and exercise regularly, your doctor may prescribe medicines to help lower
your cholesterol. Even if you begin drug treatment, you will need to continue
TLC. TLC lowers your risk not only by lowering LDL but also in other ways and
helps keep down the dose of LDL-lowering medication you have to take. Drug
treatment controls but does not "cure" high blood cholesterol. Therefore, you
must continue taking your medicine to keep your cholesterol level in the
recommended range.
The five major types of cholesterol-lowering
medicines are:
- Statins
- Very effective in lowering LDL (bad)
cholesterol levels
- Safe for most people
- Rare side effects to watch for are muscle and
liver problems
-
Bile Acid Sequestrants (seh-KWES-trants)
- Help lower LDL cholesterol levels
- Sometimes prescribed with statins
- Not usually prescribed as the only medicine
to lower cholesterol
-
Nicotinic (Nick-o-TIN-ick) Acid
- Lowers LDL cholesterol and triglycerides, and
raises HDL (good) cholesterol
- Should only be used under a doctor's
supervision
-
Fibrates
- Lower triglycerides
- May increase HDL (good) cholesterol levels
- When used with a statin, may increase the
chance of muscle problems
- Ezetimibe
- Lowers LDL cholesterol
- Acts within the intestine to block
cholesterol absorption
When you are under treatment, you will be checked
regularly to:
- Make sure your cholesterol level is controlled
- Check for other health problems
You may take medicines for other health problems. It
is important that you take ALL medicines as your doctor prescribes. The
combination of medicines may lower your risk for heart disease or heart attack.
When trying to lower your cholesterol or keep it
low, it is important to remember to follow your treatments for other conditions
you may have, such as high blood pressure. Get help with quitting smoking and
losing weight if they are risk factors for you.
____________ 1If
your HDL cholesterol is 60 mg/dL or higher, subtract 1 from your total
count.
Key Points
- Cholesterol is a fat-like substance that is made
in your body. Cholesterol is also in some foods that you eat. Your body needs
some cholesterol to work the right way. Your body makes all the cholesterol it
needs.
- Too much cholesterol in the blood is called high
blood cholesterol or hypercholesterolemia.
- High blood cholesterol increases the chance of
having a
heart
attack or some other symptom of heart disease, like chest pain (angina).
- Lowering cholesterol is important for
everyoneyoung, middle-aged, and older adults, and both men and women.
- Eating too much saturated fat, trans
fat, and cholesterol raises the level of cholesterol in your blood.
- Too much cholesterol in your blood can build up
in the walls of arteries. This is called plaque.
- There are no signs or symptoms of high blood
cholesterol. Many people don't know that their cholesterol level is too high.
- High blood cholesterol is diagnosed by checking
cholesterol levels in your blood.
- A blood test called a lipoprotein profile
measures the cholesterol levels in your blood and is the recommended test.
- It is important that everyone age 20 and older
get their cholesterol checked at least once every 5 years.
- Many people are able to lower their cholesterol
levels by eating a diet low in saturated fat, trans fat, and
cholesterol, increasing physical activity, and losing weight if needed (the TLC
program).
- Some people will need to take medicines
prescribed by their doctor to lower their cholesterol in addition to following
the TLC program.
Links to Other Information About High Blood
Cholesterol
NHLBI Resources
Non-NHLBI Resources
Clinical Trials
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