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What Is Pulmonary Hypertension?
Pulmonary hypertension, 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 condition worsens, its symptoms may limit all physical activity.
PH begins with inflammation and changes in the cells that line your pulmonary arteries. Other factors also can affect the pulmonary arteries and cause PH. For example, the condition may develop if:
- 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 your heart to push blood through your pulmonary arteries and into your lungs. As a result, the pressure in your arteries rises. Also, because your heart is working harder than normal, your right ventricle becomes strained and weak.
Your heart may become so weak that it can’t pump enough blood to your 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 arteries is higher than 25 mmHg at rest or 30 mmHg during physical activity. The pressure in normal pulmonary arteries is 8–20 mmHg at rest. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
Other diseases or conditions, such as heart and lung diseases or blood clots, usually cause PH. Some people inherit the condition (that is, their parents pass the genes for PH on to them). In some cases, the cause isn’t known.
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.
What Causes Pulmonary Hypertension?
Pulmonary hypertension (PH) begins with inflammation and changes in the cells that line your pulmonary arteries. These changes make it hard for your heart to push blood through your pulmonary arteries and into your lungs. Thus, the pressure in the arteries rises, causing PH.
Many 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 the condition may be inherited. Some diseases and conditions also can cause group 1 PAH. Examples include HIV infection, congenital heart disease, and sickle cell disease. Also, the use of street drugs (such as cocaine) and certain diet medicines can lead to PAH.
Many diseases and conditions can cause groups 2 through 5 PH (often called secondary PH), including:
- Mitral valve disease
- Lung diseases, such as COPD
- Sleep apnea
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. It affects women more often than men. People who have group 1 PAH tend to be overweight.
PH that occurs with another disease or condition is more common. 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
- about the diseases, conditions, and factors that cause PH, go to “Types of Pulmonary Hypertension.”)
- Those who use street drugs (such as cocaine) or certain diet medicines.
- Those who live at high altitudes.
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
- Chest pain
- A racing heartbeat
- Pain on the upper right side of the abdomen
- Decreased appetite
As PH worsens, you may find it hard to do any physical activities. At this point, other signs and symptoms may include:
- Feeling light-headed, 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 condition has no early signs or symptoms. When symptoms do occur, they’re often like those of other heart and lung conditions, such as asthma. This makes PH hard to diagnose.
Medical and Family Histories
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 will want to know whether you have any family members who have or have had PH. People who have a family history of PH are at higher risk for the condition.
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 color. These are signs of PH.
Diagnostic Tests and Procedures
Your doctor may recommend tests and procedures to confirm a diagnosis of PH and to look for its underlying cause. Your doctor also will use test results to find out the severity of your PH.
Tests and Procedures To Confirm a Diagnosis
Echocardiography. Echocardiography, or echo, uses sound waves to create a moving picture of your heart. This test can estimate the pressure in your pulmonary arteries. Echo 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 the structures in your chest, such as your heart, lungs, and blood vessels. 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. A chest x ray also may show signs of an underlying lung disease that’s causing or contributing to PH.
EKG (electrocardiogram). An EKG is a simple, painless test that records the heart’s electrical activity. This test 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 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 threaded into the right side of your heart and into the pulmonary arteries. Through the tube, your doctor can do tests and treatments on your heart.
Tests To Look for the Underlying Cause of Pulmonary Hypertension
PH has many causes, so many tests may need to be done to find its underlying cause.
Chest CT scan. A chest computed tomography scan, or chest CT scan, creates pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. These pictures can show signs of PH or a condition that may be causing PH.
Chest MRI. Chest magnetic resonance imaging, or chest MRI, shows how your right ventricle is working. The test also shows blood flow in your lungs. Chest MRI also can help detect signs of PH or an underlying condition causing PH.
Lung function tests. Lung function tests measure 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 detect a lung disease that may be causing PH.
Polysomnogram (PSG). This test records brain activity, eye movements, heart rate, and blood pressure while you sleep. A PSG also measures the level of oxygen in your blood. A low oxygen level during sleep is common in PH, and it can make the condition worse. A PSG usually is done while you stay overnight at a sleep center.
Lung ventilation/perfusion (VQ) scan. A lung VQ scan measures air and blood flow in your lungs. This test can help detect 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.
Finding Out the Severity of Pulmonary Hypertension
Exercise testing is used to find out the severity of PH. This testing consists of either a 6-minute walk test or a cardiopulmonary exercise test. 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.
During exercise testing, your doctor will rate your activity level. Your level is linked to the severity of your PH. 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 with the previous one.
How Is Pulmonary Hypertension Treated?
Pulmonary hypertension (PH) has no cure. However, 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 its severity.
Group 1 Pulmonary Arterial Hypertension
Group 1 pulmonary arterial hypertension (PAH) includes PH that’s inherited, that has no known cause, or that’s caused by certain drugs or conditions. Treatments for group 1 PAH include medicines and medical procedures.
Your doctor may prescribe 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.
Your doctor may prescribe medicines that are taken by mouth, inhaled, or injected.
Examples of medicines for group 1 PAH include:
- Phosphodiesterase-5 inhibitors, such as sildenafil
- Prostanoids, such as epoprostenol
- Endothelin receptor antagonists, such as bosentan and ambrisentan
- Calcium channel blockers, such as diltiazem
Your doctor may prescribe one or more of these medicines. To find out which of these medicines works best, you’ll likely have an acute vasoreactivity test. This test shows how the pressure in your pulmonary arteries reacts to certain medicines. The test is done during right heart catheterization.
Medical and Surgical Procedures
If you have group 1 PAH, your doctor may recommend 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 upper chambers of your heart). This wall is called the septum.
A tiny balloon on the tip of the tube is inflated. This creates 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.
Heart–lung transplant. A heart–lung transplant is surgery in which both the heart and lung are replaced with healthy organs from a deceased donor.
Group 2 Pulmonary Hypertension
Conditions that affect the left side of the heart, such as mitral valve disease, can cause group 2 PH. Treating the underlying condition will help treat PH. Treatments may include lifestyle changes, medicines, and surgery.
Group 3 Pulmonary Hypertension
Lung diseases, such as COPD (chronic obstructive pulmonary disease) and interstitial lung disease, can cause group 3 PH. Certain sleep disorders, such as sleep apnea, also can cause group 3 PH.
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. Oxygen therapy can be done at home or in a hospital. Your doctor also may recommend other treatments if you have an underlying lung disease.
Group 4 Pulmonary Hypertension
Blood clots in the lungs or blood clotting disorders can cause group 4 PH. If you have this type of PH, your doctor will likely prescribe blood-thinning medicines. These medicines prevent clots from forming or getting larger. Sometimes doctors use surgery to remove scarring in the pulmonary arteries due to old blood clots.
Group 5 Pulmonary Hypertension
Various diseases and conditions, such as thyroid disease and sarcoidosis, can cause group 5 PH. An object, such as a tumor, pressing on the pulmonary arteries also can cause group 5 PH. Group 5 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, also called 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 sometimes is used to control the heart rate if abnormal heart rhythms, such as atrial
- fibrillation or atrial flutter, occur.
- Oxygen therapy. This treatment raises the level of oxygen in your blood.
- Physical activity. Regular activity may help improve your ability to be active. Talk with your doctor about a physical activity plan that’s safe for you.