What Is Pulmonary Hypertension?
Pulmonary hypertension (PULL-mun-ary
HI-per-TEN-shun), or PH, is increased pressure in the pulmonary arteries. These
arteries carry blood from your heart to your lungs to pick up oxygen.
PH causes symptoms such as shortness of breath
during routine activity (for example, climbing two flights of stairs),
tiredness, chest pain, and a racing heartbeat. As the disease worsens, its
symptoms may limit all physical activity.
Overview
The lower right chamber of your heart, the right
ventricle (VEN-trih-kul), pumps blood to your pulmonary arteries. The blood
then travels to your lungs, where it picks up oxygen. This oxygen-rich blood is
pumped to the rest of your body. (For more information, see the Diseases and
Conditions Index article on
How
the Heart Works.)
Three types of changes can affect the pulmonary
arteries and cause PH:
- The walls of the arteries tighten.
- The walls of the arteries are stiff at birth or
become stiff from an overgrowth of cells.
- Blood clots form in the arteries.
These changes make it hard for the heart to push
blood through the arteries and into the lungs. Thus, the pressure in the
arteries rises. Also, as a result of the heart working harder, the right
ventricle becomes strained and weak.
The heart may become so weak that it can't pump
enough blood to the lungs. This causes
heart
failure. Heart failure is the most common cause of death in people who have
PH.
PH is divided into five groups based on its causes.
In all groups, the average pressure in the pulmonary artery is higher than 25
mmHg at rest or 30 mmHg during physical activity. The pressure in a normal
pulmonary artery is about 15 mmHg at rest. (The mmHg is millimeters of
mercurythe units used to measure blood pressure.)
Usually, other diseases or conditions, such as heart
and lung diseases or blood clots, cause PH. Some people inherit the condition.
In some cases, the cause isn't known.
Outlook
PH has no cure. However, research for new treatments
is ongoing. The earlier PH is treated, the easier it is to control.
Treatments include medicines, procedures, and other
therapies. These treatments can relieve PH symptoms and slow the progress of
the disease. Lifestyle changes also can help control symptoms.
Types of Pulmonary Hypertension
The World Health Organization divides pulmonary
hypertension (PH) into five groups. These groups are organized based on the
cause of the disease.
In all groups, the average pressure in the pulmonary
artery is higher than 25 mmHg at rest or 30 mmHg during physical activity. The
pressure in a normal pulmonary artery is about 15 mmHg at rest.
(Note that group 1 is called pulmonary arterial
hypertension (PAH) and groups 2 through 5 are called pulmonary hypertension.
However, together all groups are called pulmonary hypertension.)
Group 1 PAH includes:
- PAH that has no known cause.
- PAH that's inherited (passed from parents to
children through the genes).
- PAH that's caused by conditions such as:
- Congenital
heart disease. This is heart disease that's present at birth.
- HIV infection.
- The use of certain diet medicines and street
drugs (such as cocaine).
- Thyroid diseases.
Group 2 includes PH with left heart disease.
Conditions that affect the left side of the heart, such as
mitral
valve disease or long-standing
high
blood pressure, can cause left heart disease and PH.
Group 3 includes PH linked to lung conditions such
as COPD
(chronic obstructive pulmonary disease) and interstitial (IN-ter-STISH-al) lung
disease. Interstitial lung disease refers to a group of lung diseases that
cause scarring of the lung tissue. Group 3 also includes PH linked to sleep
disorders that cause breathing problems, such as
sleep
apnea.
Group 4 includes PH due to blood clots in the lungs
or blood clotting disorders. This group also includes PH due to
sickle
cell anemia.
Group 5 includes PH due to various other diseases or
conditions. Examples include
sarcoidosis,
Langerhans cell histiocytosis, and
lymphangioleiomyomatosis
(LAM). This type of PH also may be due to an object, such as a tumor, pressing
on the pulmonary blood vessels.
Sometimes other terms are used to describe the
different types of PH. Group 1 PAH that has no known cause may be called
primary or idiopathic (id-ee-o-PATH-ick) PAH. When PH occurs with or is caused
by another disease or condition, it may be called secondary PH.
Other Names for Pulmonary Hypertension
Group 1 pulmonary arterial hypertension (PAH) that
occurs without a known cause is often called primary PAH or idiopathic PAH
(IPAH).
Group 1 PAH that occurs with a known underlying
disease or condition is often called associated PAH. For example, PAH that
occurs in a patient who has scleroderma might be called "PAH occurring in
association with scleroderma," or simply "scleroderma-associated PAH."
Groups 25 PH are sometimes called secondary
PH.
What Causes Pulmonary Hypertension?
Pulmonary hypertension (PH) is the result of a
process that begins with changes in the cells that line your lungs' arteries.
This process includes three types of changes that affect the pulmonary
arteries:
- The walls of the arteries tighten.
- The walls of the arteries are stiff at birth or
become stiff from an overgrowth of cells.
- Blood clots form in the arteries.
These changes make it hard for the heart to push
blood through the arteries and into the lungs. Thus, the pressure in the
arteries rises, resulting in PH.
A number of different factors can contribute to the
process that leads to the different types of
PH.
Group 1 pulmonary arterial hypertension (PAH) may
have no known cause, or it may be inherited (passed from parents to children
through the genes). Certain diseases and conditions, such as
congenital
heart disease, HIV, and thyroid disease, also can cause this type of PH.
Also, the use of certain diet medicines and street drugs (such as cocaine) can
lead to this type of PH.
Many different diseases and conditions can lead to
the development of groups 2 through 5 PH (often called secondary PH),
including:
For more information about the types of PH and the
diseases, conditions, and factors that can contribute to PH, see
"Types of Pulmonary Hypertension."
Who Is At Risk for Pulmonary Hypertension?
The exact number of people who have pulmonary
hypertension (PH) isn't known. Group 1 pulmonary arterial hypertension (PAH)
without a known cause is rare. PH that occurs with another disease or condition
is more common.
Anyone can develop PH. However, PAH that has no
known cause affects about two to three times as many women as men. PH usually
develops between the ages of 20 and 60, but it can occur at any age.
People who are at increased risk for PH include:
- Those who have a family history of the
condition.
- Those who have certain diseases or conditions,
such as heart and lung diseases, liver disease, HIV infection, or blood clots
in the pulmonary arteries. (For more information on diseases, conditions, and
factors that can lead to PH, see "Types of Pulmonary
Hypertension.")
- Those who use certain diet medicines or street
drugs (such as cocaine).
What Are the Signs and Symptoms of Pulmonary
Hypertension?
Signs and symptoms of pulmonary hypertension (PH)
may include:
- Shortness of breath during routine activity, such
as climbing two flights of stairs
- Tiredness
- Chest pain
- A racing heartbeat
As PH worsens, you may find it hard to do any
physical activities. At this point, other signs and symptoms may include:
- Feeling lightheaded, especially during physical
activity
- Fainting at times
- Swelling in your legs and ankles
- A bluish color on your lips and skin
How Is Pulmonary Hypertension Diagnosed?
Your doctor will diagnose pulmonary hypertension
(PH) based on your medical and family histories, a physical exam, and the
results from tests and procedures.
PH can develop slowly. In fact, you may have it for
years and not know it. This is because the disease has no early symptoms.
When symptoms do develop, they're often like those
of other heart and lung conditions, such as
asthma.
This makes PH hard to diagnose.
Medical and Family Histories
To learn about your medical history, your doctor may
ask about your signs and symptoms and how and when they began. He or she also
may ask whether you have other medical conditions that can cause PH.
Your doctor also may ask whether you have any family
members who have or have had PH. People who have a family history of PH are at
increased risk for the condition.
Physical Exam
During the physical exam, your doctor will listen to
your heart and lungs with a stethoscope. He or she also will check your ankles
and legs for swelling and your lips and skin for a bluish tint. These are signs
of PH.
Diagnostic Tests and Procedures
You may need tests and procedures to confirm a
diagnosis of PH and to look for the underlying cause of the disease. Your
doctor also will use test results to find out the severity of your PH.
Tests and Procedures To Confirm a Diagnosis
Echocardiography. This test uses
sound waves to create a moving picture of your heart.
Echocardiography
(EK-o-kar-de-OG-ra-fee) can estimate the pressure in your pulmonary arteries.
The test also can show the size and thickness of your right ventricle and how
well it's working.
Chest x ray. A
chest
x ray takes pictures of your heart and lungs. This test can show whether
your pulmonary arteries and right ventricle are enlarged. The pulmonary
arteries and right ventricle may get larger if the right ventricle has to work
hard to pump blood through the pulmonary arteries.
Also, a chest x ray may show signs of an underlying
lung disease that may be causing or contributing to PH.
EKG (electrocardiogram). An
EKG
is a simple test that shows how fast your heart is beating. It also shows
whether your heart's rhythm is steady or irregular. An EKG may show whether
your right ventricle is enlarged or strained.
Right heart catheterization. This
procedure measures the pressure in your pulmonary arteries. It also shows how
well your heart is pumping blood to the rest of your body.
Right
heart catheterization (KATH-e-ter-i-ZA-shun) can find any leaks between the
left and right side of the heart.
During this procedure, a thin, flexible tube called
a catheter is put into a blood vessel in your groin (upper thigh) or neck. The
tube is then threaded into the right side of your heart and into the pulmonary
arteries. Through the tube, your doctor can do diagnostic tests and test
treatments on your heart.
Tests To Look for the Underlying Cause of Pulmonary
Hypertension
Lung function tests. Lung
function tests measure the size of your lungs, how much air you can breathe
in and out, how fast you can breathe air out, and how well your lungs deliver
oxygen to your blood. These tests can help find an underlying lung disease that
may be causing PH.
Overnight oximetry. This test
measures the level of oxygen in your blood overnight. A low oxygen level during
sleep is common in PH, and it can cause the condition to worsen.
For this test, a small light is attached to your
fingertip, earlobe, or toe. A machine that's attached to the light measures the
amount of oxygen in your blood throughout the night. In the morning, the light
is removed and your oxygen levels are recorded. Overnight oximetry can be done
at home or in a sleep lab.
Lung ventilation/perfusion (VQ)
scan. This test measures air and blood flow in your lungs. A
lung
VQ scan can show whether there are blood clots in your lung's blood
vessels.
Blood tests.
Blood
tests are used to rule out other diseases, such as HIV, liver disease, and
autoimmune diseases like rheumatoid arthritis.
Exercise testing. Exercise testing
consists of either a 6-minute walk test or a cardiopulmonary exercise test.
These tests can help find out whether another disease or condition is causing
your symptoms.
A 6-minute walk test measures the distance you can
quickly walk in 6 minutes. A cardiopulmonary exercise test measures how well
your lungs and heart work while you exercise on a treadmill or bicycle.
Finding Out the Severity of Pulmonary
Hypertension
Exercise testing is used to find out how severe PH
is. During this test, your doctor will rate your activity level. Your level is
linked to how severe your PH is. The rating system ranges from class 1 to class
4.
- Class 1 has no limits. You can do regular
physical activities, such as walking or climbing stairs. These activities don't
cause PH symptoms, such as tiredness, shortness of breath, or chest pain.
- Class 2 has slight or mild limits. You're
comfortable while resting, but regular physical activity causes PH
symptoms.
- Class 3 has marked or noticeable limits. You're
comfortable while resting. However, walking even one or two blocks or climbing
one flight of stairs can cause PH symptoms.
- Class 4 has severe limits. You're not able to do
any physical activity without discomfort. You also may have PH symptoms while
at rest.
Over time, you may need more exercise tests to find
out how well your treatments are working. Each time testing is done, your
doctor will compare your activity level to the previous one.
How Is Pulmonary Hypertension Treated?
Pulmonary hypertension (PH) has no cure, but
treatment may help relieve symptoms and slow the progress of the disease.
PH is treated with medicines, procedures, and other
therapies. Treatment will depend on what type of PH you have and how severe it
is. (For more information, see "Types of Pulmonary
Hypertension.")
Group 1 Pulmonary Arterial Hypertension
This type of PH includes PH that's inherited, that
has no known cause, or that's caused by certain conditions. Treatment for group
1 pulmonary arterial hypertension (PAH) includes medicines or medical
procedures.
Medicines
If you have group 1 PAH, you may need medicines to
relax the blood vessels in your lungs and reduce excess cell growth in the
blood vessels. As the blood vessels relax, more blood can flow through
them.
Examples of these medicines include
phosphodiesterase-5 inhibitors, prostanoids, endothelin receptor antagonists,
and calcium channel blockers.
To find out which of these medicines will work best,
you'll likely have an acute vasoreactivity test. This test shows how the
pressure in your pulmonary arteries reacts to certain medicines. This test is
done during
right
heart catheterization.
Medical and Surgical Procedures
If you have group 1 PAH, you may need one or more of
the following procedures.
Atrial septostomy. For this
procedure, a thin, flexible tube called a catheter is put into a blood vessel
in your leg and threaded to your heart. The tube is then put through the wall
that separates your right and left atria (the two upper chambers of your
heart). This wall is called the septum.
A tiny balloon on the tip of the tube is inflated to
create an opening between the atria. This procedure relieves the pressure in
the right atria and increases blood flow. Atrial septostomy is rarely done in
the United States.
Lung transplant. A lung transplant
is surgery to replace a person's diseased lung with a healthy lung from a
deceased donor. This procedure may be used for people who have severe lung
disease that's causing PAH.
Heartlung transplant. A
heartlung transplant is surgery in which both the heart and lung are
replaced with healthy organs from a deceased donor.
Group 2 Pulmonary Hypertension
Group 2 PH is caused by conditions that affect the
left side of the heart, such as
mitral valve disease. Treating these conditions also will help treat PH.
Treatments may include lifestyle changes, medicines, and surgery.
Group 3 Pulmonary Hypertension
Group 3 PH is linked to lung conditions, such as
COPD
(chronic obstructive pulmonary disease) and interstitial lung disease. Group 3
PH also may be linked to certain sleep disorders, such as
sleep
apnea.
If you have this type of PH, you may need oxygen
therapy. This treatment raises the level of oxygen in your blood. You'll likely
get the oxygen through soft, plastic prongs that fit into your nose. You can
get oxygen therapy at home or in a hospital.
Your doctor also may recommend other treatments if
you have an underlying lung disease.
Group 4 Pulmonary Hypertension
This type of PH is due to blood clots in the lungs,
blood clotting disorders, or
sickle
cell anemia. If you have this type of PH, your doctor will likely prescribe
anticoagulants, or "blood thinners." These medicines prevent clots from forming
or from getting larger.
In some cases, surgery is used to remove scarring in
the pulmonary arteries due to old blood clots.
Group 5 Pulmonary Hypertension
Various diseases and conditions cause group 5 PH.
Examples include
sarcoidosis,
Langerhans cell histiocytosis, and
lymphangioleiomyomatosis
(LAM). This type of PH also may be due to an object, such as a tumor, pressing
on the pulmonary blood vessels.
This type of PH is treated by treating its
cause.
All Types of Pulmonary Hypertension
Several treatments may be used for all types of PH.
These treatments include:
- Diuretics, or "water pills." These medicines help
reduce fluid buildup in your body, including swelling in your ankles and
feet.
- Blood-thinning medicines. These medicines help
prevent blood clots from forming or getting larger.
- Digoxin. This medicine helps the heart beat
stronger and pump more blood. Digoxin is sometimes used to control the heart
rate when certain abnormal heart rhythms occur, such as
atrial
fibrillation or atrial flutter.
- Oxygen therapy. This treatment raises the level
of oxygen in your blood.
- Physical activity. Regular activity may help
improve your ability to be active. Your doctor can help you create an exercise
plan that's safe for you.
Research on new treatments for PH is ongoing. These
treatments offer hope for the future. Talk to your doctor about whether you
should consider participating in research studies.
Living With Pulmonary Hypertension
Pulmonary hypertension (PH) has no cure. However,
you can work with your doctor to manage your symptoms and slow the progress of
the disease.
Ongoing Care
Follow your treatment plan and call your doctor if
your PH symptoms worsen or change. The earlier symptoms are addressed, the
easier it is to treat them. Some symptoms, such as chest pain, may require
emergency treatment. Talk to your doctor about when you should call him or her
and when to seek emergency care.
Also, talk to your doctor before taking any
over-the-counter medicines. Certain medicines can make your PH worse or
interfere with the medicines you're taking for PH. Ask your doctor whether you
should get a
pneumonia
vaccine and a yearly flu shot.
Know the names of your medicines and how they work.
Keep a list of your medicines with you. Don't stop or change your medicines
unless you talk with your doctor.
Pay careful attention to your weight. You may want
to keep a daily record of your weight. You should weigh yourself at the same
time each day. If you notice a rapid weight gain (2 or more pounds in 1 day or
5 or more pounds in 1 week), call your doctor. This may be a sign that your
condition is worsening.
Pregnancy is risky for women who have PH. Consider
using birth control if there's a chance you may become pregnant. Talk to your
doctor about which birth control methods are right for you.
Lifestyle Changes
Making lifestyle changes can help you manage your
symptoms. These changes will depend on the type of PH you have. Talk to your
doctor about which steps can help you.
Quit Smoking
If you smoke, quit. Smoking makes PH symptoms worse.
Ask your doctor about programs and products that can help you quit. Also, avoid
exposure to secondhand smoke.
Follow a Healthy Diet
Follow a healthy diet and maintain a healthy weight.
A healthy diet includes a variety of fruits, vegetables, and whole grains. It
also includes lean meats, poultry, fish, and fat-free or low-fat milk or milk
products. A healthy diet also is low in saturated fat, trans fat,
cholesterol, sodium (salt), and added sugar.
Talk to your doctor about whether you need to limit
the amount of salt and fluids in your diet. Ask him or her whether you also
need to regulate foods that contain vitamin K. These foods can affect how well
blood-thinning medicines work. Vitamin K is found in green leafy vegetables and
some oils, such as canola and soybean oil.
For more information on following a healthy diet,
see the National Heart, Lung, and Blood Institute's
Aim for a
Healthy Weight Web site,
"Your
Guide to a Healthy Heart," and
"Your
Guide to Lowering Your Blood Pressure With DASH."
All of these resources include general advice about
healthy eating. The DASH eating plan focuses on foods that are lower in salt,
which may be helpful if your doctor advises you to reduce the salt in your
diet.
Do Physical Activity
Do regular physical activity, such as walking. This
will keep your muscles strong and help you stay active. Talk to your doctor
about how much activity is safe for you. Your doctor may tell you to limit or
avoid certain activities, such as:
- Those that cause straining, such as lifting heavy
objects or weights.
- Being in a hot tub or sauna or taking long baths.
These activities can lower your blood pressure too much.
- Flying in an airplane or traveling to
high-altitude areas. Your doctor may ask you to use oxygen during air
travel.
Avoid activities that cause breathing problems,
dizziness, or chest pain. If you have any of these symptoms, seek care right
away.
Key Points
- Pulmonary hypertension (PH) is increased pressure
in the pulmonary arteries. These arteries carry blood from your heart to your
lungs to pick up oxygen.
- Three types of changes can affect the pulmonary
arteries and can cause PH: the walls of the arteries tighten, the walls of the
arteries are stiff at birth or become stiff from an overgrowth of cells, or
blood clots form in the arteries.
- These changes make it hard for the heart to push
blood through the arteries and into the lungs. Thus, the pressure in the
arteries rises. Also, as a result of the heart working harder, the right
ventricle becomes strained and weak.
- The heart may become so weak that it can't pump
enough blood to the lungs. This causes
heart
failure. Heart failure is the most common cause of death in people who have
PH.
- PH is divided into five groups based on its
causes. In all groups, the average pressure in the pulmonary artery is higher
than 25 mmHg at rest or 30 mmHg during physical activity. The pressure in a
normal pulmonary artery is about 15 mmHg at rest.
- Usually, other diseases or conditions, such as
heart and lung diseases or blood clots, cause PH. Some people inherit the
condition. In some cases, the cause isn't known.
- The exact number of people who have PH isn't
known. Group 1 pulmonary arterial hypertension (PAH) without a known cause is
rare. PH that occurs with another disease or condition is more common.
- PH causes symptoms such as shortness of breath
during routine activity (for example, climbing two flights of stairs),
tiredness, chest pain, and a racing heartbeat. As the disease worsens, its
symptoms may limit all physical activity.
- Your doctor will diagnose PH based on your
medical and family histories, a physical exam, and the results from tests and
procedures. PH can develop slowly. In fact, you may have it for years and not
know it. This is because the disease has no early symptoms. When symptoms do
develop, they're often like those of other heart and lung conditions, such as
asthma.
This makes PH hard to diagnose.
- PH has no cure, but treatments may help relieve
symptoms and slow the progress of the disease. PH is treated with medicines,
procedures, and other therapies. Treatment will depend on what type of PH you
have and how severe it is. The earlier PH is treated, the easier it is to
control.
- You can work with your doctor to manage your
symptoms and slow the progress of PH. Get ongoing care. Follow your treatment
plan and call your doctor if your symptoms worsen or change. Make lifestyle
changes, such as eating healthy, quitting smoking, and doing regular physical
activity.
- Research on new treatments for PH is ongoing.
These treatments offer hope for the future. Talk to your doctor about whether
you should consider participating in research studies.
Links to Other Information About Pulmonary
Hypertension
NHLBI Resources
Non-NHLBI Resources
Clinical Trials
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