Pulmonary Arterial Hypertension (PAH)

Last Updated 11/02/2020

Authors:Vijay P Balasubramanian, MD, FCCP, UCSF; Wassim H Fares, MD, FCCP; Deborah Jo Levine, MD, MS, FCCP; Sandeep Sahay, MD, FCCP; and Victor J Test, MD, FCCP

About Pulmonary Arterial Hypertension (PAH)

Key facts about Pulmonary Arterial Hypertension
  • Pulmonary arterial hypertension (PAH) can be caused by many conditions. Therefore, the treatment option your provider chooses depends on the cause of your PAH.
  • PAH can be difficult to diagnose because its symptoms, such as shortness of breath, are similar to other diseases.
  • PAH will get worse without the right treatment.
  • In most cases, PAH can be treated but not cured.

Pulmonary arterial hypertension (PAH) is a rare and serious disease. It develops when the small blood vessels in your lungs become narrow and scarred, which then raise the blood pressure in your lungs. PAH can be hard to diagnose and treat, so it is important that you work closely with your health care provider.

How Pulmonary Arterial Hypertension affects your body

To understand how PAH affects your body, you first need to understand how your lungs contribute to the normal flow of blood. Your heart is divided into two sides: the left side and the right side. Each side has an atrium (a receiving chamber) and a ventricle (a pumping chamber). Each side of your heart pumps blood but for different reasons. The left side of your heart pumps blood full of oxygen and vital nutrients through your arteries to cells and tissues throughout the body. Because the blood has to go a long distance from the heart, it needs higher pressure. When you get your blood pressure checked, your provider is measuring the pressure that pushes the blood throughout the body.

After the blood delivers its oxygen and nutrient supply, it returns through veins to the right side of your heart, which pumps the blood to your lungs. The pump in the right side of your heart doesn’t need a lot of pressure because your heart and lung are close together. This lower pressure is called pulmonary pressure and is measured differently from the blood pressure in the left side of your heart.

When the pumping pressure is too high in the left side of the heart, it is called hypertension or high blood pressure. When the pumping pressure is too high in the right side of the heart, it is called pulmonary hypertension (PH).

How serious is Pulmonary Arterial Hypertension?

PAH is one form of PH. In PAH, high blood pressure in the right side of the heart results when blood vessels in your lungs have thickened and narrowed. Because of this scarring, the right side of your heart has to pump harder—that is, it must use higher pressure—to move your blood. Because the right side of your heart is working so hard to keep up with the blood flow, your heart becomes weak and, over time, may fail. When your heart is weak, it takes longer to move blood through the lungs to pick up oxygen, so your oxygen levels may become lower than normal. Oxygen is vital not only to cells and tissue but to maintain healthy brain function, too. That’s why diagnosing and treating PAH is critical.

Measuring blood pressure

If you’re like most people, you’ve had your blood pressure checked with a blood pressure cuff. This cuff measures the pressure in the left side of your heart in millimeters of mercury (or mm Hg). Your blood pressure measurement has two parts:

  • Systolic. The larger number is the measure of the pressure when your heart beats.
  • Diastolic. The smaller number is the measure of the pressure when your heart rests between beats.

A normal blood pressure level is 120 (systolic) over 80 (diastolic).

In the right side of your heart, the pressure measures the blood vessels in the lungs, not your heart. This measure is your pulmonary artery pressure (PAP). Normal PAP is 8 to 20 mm Hg at rest. If this measure is higher than 25 mm Hg at rest or 30 mm Hg during physical activity, it is considered high and qualifies as PH.

What causes Pulmonary Arterial Hypertension?

Conditions commonly associated with PAH include:

  • Connective tissue or autoimmune diseases, such as scleroderma, lupus, or rheumatoid arthritis
  • Cirrhosis of the liver
  • HIV infection
  • Methamphetamine or cocaine use
  • Congenital heart defects
  • An inherited disease (rare)

PAH that occurs when no other disease is present is called idiopathic PAH.

Navigating PAH

Living Well Patient Guide

PAH Infographic

PAH Infographic

PAH Mythbusters

PAH Myths Busted

The Living Well with Pulmonary Arterial Hypertension patient guide will introduce you to PAH – its causes, symptoms and risk factors; how it is diagnosed; how it is treated; and how to manage the condition to minimize its impact.

This patient education material and other collateral pieces are generously supported by a grant from Bayer.

Symptoms of Pulmonary Arterial Hypertension

PAH can be challenging to diagnose because its symptoms are similar to those of other diseases, including:

Common symptoms of PAH include:

  • Shortness of breath, especially during exercise (As the disease progresses, though, you may experience shortness of breath even during rest.)
  • Fatigue (tiredness)
  • Swelling of the feet, legs, belly, or neck
  • Chest pain
  • Palpitations (heart pounding in the chest)
  • Fainting or dizziness
  • In rare cases, coughing up blood or a change in voice

What are the risk factors for Pulmonary Arterial Hypertension?

Risk factors for PAH include:

  • Obesity
  • Illegal drug use
  • Family history of PH
  • Some appetite-suppressant medications
  • Living in high altitudes
  • Sleep apnea

Diagnosing Pulmonary Arterial Hypertension

If your health care provider suspects that you have PAH, he or she will order several tests. These tests will tell your provider first whether you have PAH and second what type of PAH you have so that you can start the right treatment.

The following tests are used to diagnose PAH:

  • Blood tests. Your provider will test for potential diseases that are associated with PAH. For example, he or she may run an HIV test, thyroid tests, autoimmune disease panels to test for systemic lupus erythematosus or scleroderma, liver tests. Your provider will also run standard tests like a complete blood count (CBC) and chemistry panels. A test to measure a hormone called brain natriuretic peptide can help determine the amount of stress on your heart.
  • Chest X-ray. A chest X-ray gives your provider a picture of your heart and lungs to look for signs of PH.
  • Computed tomography (CT) scan. A CT scan captures a more detailed picture of your lungs, blood vessels, and heart.
  • Electrocardiogram. This noninvasive test shows the electrical activity in the heart and can detect abnormal heart rhythms.
  • Lung function tests. These simple breathing tests measure how much air you can hold in your lungs and how much air moves in and out of your lungs. Lung function tests may reveal other lung diseases, like asthma or pulmonary fibrosis, which often causes scarring that can narrow blood vessels in the lungs.
  • Exercise tolerance test (also known as the 6-minute walk test). This test compares your exercise capacity, oxygen levels, and symptoms over time to evaluate how they change over time and with therapy.
  • Cardiopulmonary exercise testing (CPET or CPX). This test measures how well your heart and lungs perform at rest and during exercise. CPET helps your provider understand how much oxygen your body is using, the amount of carbon dioxide your body produces, and your breathing pattern.
  • Ventilation-perfusion scan. This test measures how well air and blood flow into your lungs. The scan creates pictures that your provider looks at to see if you have blood clots in your lungs.
  • Echocardiogram. This test is a noninvasive ultrasound scan of your heart. It looks at the chambers and valves of your heart to see how big they are and how well they function. An echocardiogram can detect some signs of PH in most patients with the disease. It doesn’t directly measure PAP, but it does give your provider an idea of whether you have PH and how severe it is.
  • Cardiac magnetic resonance imaging (MRI). An MRI scanner uses magnets and radio waves to create a detailed image. A cardiac MRI creates a picture of your heart that is more accurate than an echocardiogram. It also shows the heart muscle, valves, and blood flow and may reveal congenital heart disease (that is, an abnormality in the heart that developed before birth).

In a “normal,” healthy heart, the right and left sides work separately, and no blood moves between them. In people with PH or PAH, however, blood may flow in a different pattern, which can affect how well your heart and lungs work. A cardiac MRI can show whether blood is moving between the right and left sides of the heart.

  • Right-sided heart catheterization. If any of the other tests suggest PH or PAH, your provider will likely order a right-sided heart catheterization. This test best shows which of the five forms of PH you have. For this test, the doctor places a small tube (or catheter) into a large vein in your neck, arm, or groin, advances it to the right side of your heart, and then out into the blood vessels that connect to the lung. The doctor measures the pressure in different areas of your heart and pulmonary artery. He or she can also measure how much blood your heart pumps each minute, known as cardiac output. From all these measurements, the doctor can calculate the amount of resistance to blood flow in your lungs, known as the pulmonary vascular resistance—an important indicator of how severe your PAH is.

During right-sided heart catheterization, you may undergo a trial to see if certain medications can expand, or dilate, your blood vessels. Two types of medication can be tested:

  • Medications that you breathe in (such as nitric oxide)
  • Medications given through an IV (such as prostacyclin or adenosine)

The results of this trial help your provider choose the right medication to manage your PAH.

Print out and take these checklists to your appointment to facilitate better conversations with your health-care provider.

PH PAH Prediagnosis Checklist

PH/PAH Prediagnosis Checklist

PAH Patient Diagnosis Treatment Checklist

PAH Diagnosis and Treatment Checklist

PAH Shortness of Breath Patient Checklist

PAH Shortness
of Breath Checklist

Treating Pulmonary Arterial Hypertension

In most cases, PAH can be treated but not cured. Your provider will work with you to choose a treatment based on your symptoms, the type of PAH you have, the results of your tests, your support system at home, and your personal goals. Several medications have been approved for PAH, and you will probably need to take more than one medication to get the best results. You may also need oxygen to help you breathe better.

Stick to your treatment plan!

It’s important that you follow all the instructions your provider gives you for taking your medications and changing your lifestyle to keep you in the best health possible. Finding the right medications can take some trial and error, but stay the course. Stopping medications can be dangerous and should be done only under your provider’s supervision.

Treating Pulmonary Arterial Hypertension with oxygen

Some people with PAH may need to use extra oxygen to help them breathe better and improve their daily life. Oxygen isn’t addictive, so you don’t have to worry about how much you use. Oxygen can help:

  • You breathe more easily
  • Improve your sleep, mood, and mental ability
  • Your body work better during the day

There are three types of oxygen:

  • Compressed gas oxygen, which comes in steel or aluminum containers in different sizes for home use and while you’re traveling
  • Liquid oxygen, which changes liquid into oxygen that you can breathe
  • Oxygen concentrators, which are electric devices that remove nitrogen from the air to make oxygen more concentrated

Questions to ask If your provider prescribes oxygen include:

  • How do I make sure I receive the right amount of oxygen?
  • When and how often should I use my oxygen container?
  • Which type of oxygen equipment will be best for my lifestyle?

Airlines have rules about using oxygen. You cannot travel on an airplane with an oxygen canister. Instead, you must use either an airline-supplied oxygen canister or a US Federal Aviation Administration–certified portable oxygen container. There may be other rules, as well, so check with your airline or oxygen supplier at least 2 weeks before you plan to travel.

Treating Pulmonary Arterial Hypertension with surgery (lung transplantation)

Lung transplantation is the final treatment option when other medical therapy is no longer effective.

Lung transplantation may prolong survival and improve quality of life, but it should be considered a last resort because serious complications  are associated with it, such as infections, kidney failure, and rejection. Although long-term outcomes with lung transplantation are improving, they are still far from ideal. Therefore, it’s often a complex decision that should be made with family, caregivers, your health care team, and the transplant team.

Special considerations
  • Pregnancy. Patients with PAH must not become pregnant: PAH is a risk for mother and baby. Also, many medicines used to treat PAH can be harmful to the fetus as it develops.
  • Scleroderma. Scleroderma is a chronic disease of the connective tissue (such as ligaments and tendons). Patients with scleroderma-associated PAH are at higher risk for complications and disease progression.
  • Surgery. Patients with PAH are at a higher risk when having any type of surgery. Your provider may recommend avoiding elective surgery and possibly other, more serious surgeries depending on the risks and benefits of the surgery and the potential risk of heart failure. If you do require surgery, it is best to have it done at a hospital experienced in treating patients with PAH.
  • Immunization. Patients with PAH should keep up with immunization. In particular, they should get the flu and pneumonia vaccines.

Self-care and Pulmonary Arterial Hypertension

Life with PAH can be difficult, but you can take steps to make your life easier. First and foremost, be active in your care. It’s important that you know as much about your disease and medications as possible and work with your provider to create a treatment plan that’s right for you.

Because PAH is a rare and complex disease, you should build a close relationship with a PAH specialist. You’ll also need the support of family and friends. Treatments for PAH can range from pills taken 1 to 3 times a day to medicine that you inhale several times a day to a pump that delivers medicine all the time. How you will respond to a particular medicine depends how serious your PAH is and what caused it. Treatment helps improve your survival and can reduce your symptoms.

In the beginning, you will probably need to see your provider at least every 3 to 4 months. Your provider may also order regular tests, such as echocardiograms and 6-minute walk tests. Some provider want yearly right-heart catheterization to see if the treatments are helping you.


If your PAH is well controlled, carefully structured exercise can be helpful. If your PAH isn’t under control and you still experience a lot of symptoms, however, physical activity may not be possible until your treatment works.

Pulmonary rehabilitation is an important part of treatment for PAH. It helps you reduce episodes of shortness of breath and makes your body stronger. This comprehensive, Medicare-funded outpatient program offers:

  • Structured and monitored exercise
  • Advice on nutrition
  • Detailed explanations of your how to take your medications
  • Techniques to reduce and control breathing problems
  • Education about maintaining and improving body function
  • Help to quit smoking
  • Emotional and psychological support

Pulmonary rehabilitation improves quality of life for many people with PAH. Be sure ask your provider about pulmonary rehabilitation to keep you active.


Good nutrition—eating the right foods—can also help you better manage your PAH. Some people with PAH have trouble keeping weight on. When you lose weight, you lose muscle mass, which can decrease your strength and cause other physical problems. Other people with PAH may be overweight, which adds strain to their heart and lungs. Talk to your provider about good nutrition and a good weight for you to maintain.

Here are some helpful tips for maintaining a healthy weight:

  • Eat several smaller meals throughout the day instead of three large ones.
  • Drink plenty of fluids.
  • Eat slowly, and chew your food thoroughly.
  • Make sure you’re on a low-salt diet.

Depression and Anxiety

Many people with PAH may feel depressed or anxious. In fact, depression is the rule—not the exception—for patients with complex medical problems like PAH. It also can be hard to keep up with personal relationships and maintain your regular levels of activity.

For some people, medication helps with depression, especially if the person wants to hurt him- or herself. Treatments for depression and anxiety other than medicine include talk therapy, exercise, and meetings with a support group. Never be afraid to talk to your health care team about your feelings.

A diagnosis of PAH can be difficult for the entire family. Try to remember that your family members may have feelings of depression and anxiety, too. Support groups can help both you and your family.


It can be hard to travel with PAH, so it’s important that you make plans in advance:

  • Review travel plans with your health care team to see if you need special supplies, medication, or extra oxygen. Even if you don’t usually need oxygen, you may need it if you’re traveling to a high-altitude location.
  • Know where to get medication and oxygen on your trip.

Know in advance where you can receive care on your trip in case of emergency.

Get the facts about PAH: Myths BUSTED

Lead in text


PAH is a unique disease


PAH is a form of pulmonary hypertension. It is high blood pressure in the lungs. PAH is caused by a narrowing of the small blood vessels that go to the lungs. When they become too narrow or blocked, the part of the heart that pumps blood has to work harder. That puts a strain on the heart. Identifying the cause of PAH is important. The best treatment depends on an accurate diagnosis.


PAH and pulmonary hypertension are the same thing


Pulmonary hypertension is a general term. It is high pressure in the blood vessels in the lungs. Five disease categories are associated with pulmonary hypertension (each has a different cause or symptom). PAH is one of them. It generally refers to a narrowing and scarring of the small blood vessels that go to the lungs.


An echocardiogram is the best way to diagnose PAH


An echocardiogram is a non-invasive ultrasound of the heart. It can be used to look for pulmonary hypertension. But, it is not a test that can confirm PAH.

A right-sided heart catheterization test is needed. It ensures that the form of pulmonary hypertension is PAH. This procedure is preferred. Your doctor can directly measure the pressure in the pulmonary artery.


There is no treatment for PAH


It is usually not curable. But, there are several medications that effectively treat it. Choice of medicines is based on the:

  • Patient
  • Severity
  • Cause


I have no control over my disease


PAH tends to get worse over time. However, you may be able to slow its progress by:

  • Taking the right medications
  • Having a healthy lifestyle
  • Exercising
  • Stopping smoking


There are no types of pulmonary hypertension that can be cured.


Most forms of pulmonary hypertension are treatable—not curable. But, some categories can be cured. A liver transplant can sometimes cure PAH caused by liver disease. Other types of PAH are treatable but not curable. Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is the curable form of Pulmonary Hypertension.


If I’m taking medications, I don’t have to worry about my diet.


Medications can make a big difference. It is still important to follow a healthy diet that:

  • Limits meat and fats
  • Contains lots of fruits, grains, and vegetables
  • Reduces salt and avoids extra salt.

This can help prevent water retention and swelling. Salt is hidden in foods—especially premade foods (like fast foods) and canned goods. Be aware of how much salt is in what you eat and drink.


My doctor said that I have PAH. I don’t need more tests.


PAH has many causes. It is crucial to get tested. This will help doctors:

  • Uncover the exact disease type you have
  • Determine which type of pulmonary hypertension you have
  • Decide which medication or combination of medications is best for you
  • Monitor how well you’re responding to treatment


I should not exercise if I have PAH.


Exercise helps keep your body strong and healthy. For people with PAH, doctors typically recommend a supervised cardiac or pulmonary rehabilitation program. It should be carefully designed and supervised by a trained professional. It shouldn’t tax your breathing. It should allow you to get stronger. Your doctor may suggest daily exercise. He or she can help you pick specific exercises and set the level of intensity.


I should just get a lung transplant.


Lung transplants are not done as often today as in years past, because medications are now available that are more effective. Some people with very severe disease—despite medications—may benefit from lung transplantation. This should be a last resort. A lung transplant can cure some extreme forms of pulmonary hypertension. But, it comes with significant risks and challenges. In general, people who respond well to treatment for PAH will not likely need a transplant. For people who don’t respond well or whose condition declines over time, talk with your doctor about a lung transplant.

PAY Mythbusters

PAH Myths Busted


There are several organizations and programs to help not only patients with PAH but their family members and caregivers, as well. The Pulmonary Hypertension Association helps patients find medical specialists and facilities with expertise in PAH. It also provides access to support groups.

The following websites also help patients with PH and PAH find support:

Questions to ask your provider about Pulmonary Arterial Hypertension

If you’re going to your first appointment with a primary care physician or a pulmonologist, take the time to prepare for a meaningful discussion about PH and PAH. Consider bringing a trusted friend or loved one to the appointment: This person may remember details of the visit that you forget or misunderstand, especially explanations about your condition and next steps. Some people also find it useful to record their appointments on their smartphone.

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