The blood pressure in your lungs is different from your “regular” blood pressure throughout the body. You can have normal blood pressure overall, but still have pulmonary arterial hypertension. Normally, pressure in the right side of your heart — which pumps blood to your lungs, where it collects oxygen — and in the arteries of the lungs is lower than in the rest of your body. This allows your blood to take up as much oxygen as possible. But in PAH, narrowed arteries in the lungs increase the blood pressure in the pulmonary arteries and force the right side of your heart to work harder to pump blood into the lungs. Eventually, PAH can cause the muscle of the right side of your heart to become thickened and the chamber can enlarge from working too hard, making it less effective. The result can be inadequate oxygen in your blood, which can have dangerous effects throughout your body. (1) RELATED: Your Definitive Guide to Heart Disease
What Are the Pulmonary Arteries?
The pulmonary arteries are blood vessels that carry blood from the right side of your heart through your lungs. In PAH, these blood vessels become scarred and narrowed, leading to reduced blood flow and a buildup of blood pressure in the area. (1,2)
Common Synonyms for Pulmonary Arterial Hypertension
PAH is also known by the following names:
Pulmonary artery hypertensionPrecapillary pulmonary hypertensionPrimary pulmonary hypertensionPrimary obliterative pulmonary vascular disease (2)
Subdivisions of Pulmonary Arterial Hypertension
There are three subtypes of PAH. Heritable pulmonary arterial hypertension (HPAH) This type of PAH is a genetic condition, caused by mutations in at least one known gene. It accounts for 15 to 20 percent of all cases. Associated pulmonary arterial hypertension (APAH) This refers to PAH caused by an underlying health condition. Potential causes of associated PAH include connective tissue disorders (like scleroderma or lupus), heart abnormalities, certain infections (including HIV and schistosomiasis), liver cirrhosis, and exposure to certain drugs or toxins. Idiopathic pulmonary arterial hypertension (IPAH) This refers to PAH that doesn’t have any known underlying causes or diseases. (1,2) Pulmonary arterial hypertension symptoms commonly include:
Shortness of breath (especially after exertion)Fatigue or weaknessChest painDizzy spellsFaintingSwelling in your feet, legs, abdomen, or neck (1,2)
At first, you may experience shortness of breath with exercise or exertion when you have PAH. But as your disease gets worse, you may have this symptom at other times — even when you’re sitting still. (1) Some people with PAH experience swelling or puffiness because of the abnormal buildup of fluid (a condition known as edema) in certain areas of the body. (2) With more advanced PAH, it’s possible to experience chest pain, a pounding heart, dizzy spells, or fainting. (1) In advanced or severe cases of PAH, some people have an abnormal bluish color to their skin (known as cyanosis) due to low levels of oxygen in their blood. Also, in some severe cases, the right chamber (ventricle) of the heart becomes thickened (known as hypertrophy) and enlarged, reducing the function of the right ventricle and causing right-side heart failure. (2) In rare cases of PAH, people may cough up blood or experience a change in how their voice works or sounds. (1) It’s clear that a number of genetic and environmental factors can lead to PAH. In heritable PAH, mutations in a specific gene are passed on within a family. The most commonly identified gene is called BMPR2, and researchers have also identified other genes that may be involved. Some gene mutations, though, remain unidentified. (2) In associated PAH, doctors identify a health condition, drug, or toxin that they believe has led to the condition. Potential underlying health conditions include:
LupusSclerodermaCongenital heart abnormalitiesLiver disease (cirrhosis)HIV (the virus that causes AIDS)
PAH may also be caused by exposure to certain drugs or toxins, such as:
Appetite-suppressant (diet) drugsDasatinib (a cancer drug)MethamphetamineCocaine (1,2)
For reasons that aren’t clear, PAH is about three to five times more common in women than men. Idiopathic PAH — without any known underlying causes — typically affects younger women of childbearing age, and the overall age range for PAH in women is typically 30 to 60. (1,2) Newborn babies can also develop a form of PAH (called persistent pulmonary hypertension of the newborn, or PPHN) when their circulatory system doesn’t adapt to breathing air. It’s most common in full-term or post-term babies who experience a difficult birth, and can cause rapid breathing or an abnormal bluish skin color. (2) If you experience symptoms that may indicate PAH, your doctor will ask about any possible underlying diseases or risk factors, including a family history of PAH. After giving you a basic physical exam, your doctor may order the following tests.
Blood Tests
Your doctor may order tests to look for a variety of conditions that could cause low levels of blood oxygen, to rule out PAH. Your doctor may also look for conditions that could contribute to PAH, such as HIV, autoimmune diseases, or liver disease.
Breathing Tests
Tests that measure your breathing capabilities (known as pulmonary function tests) may help rule out lung diseases that can cause symptoms similar to PAH, such as asthma and emphysema. (1)
Chest X-Ray
This test is commonly used to look for conditions other than PAH that could affect your breathing. These conditions may include heart problems, pneumonia, a collapsed lung, emphysema, or cancer. (2,3)
Electrocardiogram (ECG, EKG)
This test measures the electrical activity of your heart, and can help detect certain abnormalities or strain on the right side of your heart. It’s done by attaching sensors to your skin, and is completely safe and painless (other than some possible discomfort when the sticky sensors are removed). (1,4)
Echocardiogram
This imaging test creates a moving picture of your heart using sound waves (ultrasound). It lets doctors evaluate the size and condition of the chambers of your heart, which may help detect underlying causes of PAH. (1)
Doppler Ultrasound
This ultrasound technique can be used to see how blood flows through vessels in your heart or other areas, including your lungs. Often done as part of an echocardiogram, it can be used to estimate the blood pressure in your pulmonary arteries. (1,5)
Heart Catheterization
This invasive test is typically used only when other tests can’t confirm or rule out PAH. It involves inserting a small tube (catheter) into a vein in your neck, arm, or groin, and extending it through the right side of your heart to measure the blood pressure in your lungs. (1)
Exercise Testing
Your doctor may ask you to perform a six-minute walk test, which measures how far you can walk and detects any drop in your blood oxygen levels as you exert yourself. (1)
Genetic Testing
It’s not always necessary to perform genetic testing to confirm heritable PAH — for that, you only need evidence of two or more family members with PAH. But in consultation with a genetic counselor, you may also choose to test for a genetic mutation that causes PAH. (2)
Primary vs. Secondary Pulmonary Hypertension
You may have come across the terms “primary” and “secondary” pulmonary hypertension. These terms can be confusing, because both can refer to different forms of PAH — and one can refer to both PAH and other forms of pulmonary hypertension. “Primary” pulmonary hypertension refers to idiopathic PAH, one of the three types of PAH. “Secondary” pulmonary hypertension can refer to the two other forms of PAH, or to any of the other types of pulmonary hypertension that aren’t PAH. (6) Here’s an overview of all the different types of pulmonary hypertension, showing how PAH compares with different forms of this broad condition — all of them defined by high blood pressure in the lungs. Group 1: Pulmonary Arterial Hypertension PAH is defined by stiffened or narrowed arteries in your lungs, which may be due to unknown causes, a genetic mutation, or underlying health conditions. This stiffening makes the right side of your heart work harder to pump enough blood through your lungs, which raises the blood pressure in your lungs. Group 2: Pulmonary Hypertension From Left-Sided Heart Disease Normally, the left side of your heart receives oxygen-rich blood from your lungs and pumps it through arteries to the rest of your body. But in this form of pulmonary hypertension, the left side of your heart can’t keep up with the blood it’s supposed to pump from your lungs — causing a “backup” of blood and higher pressure in your lungs. This form of pulmonary hypertension may be caused by:
Left-sided valvular heart disease (such as mitral or aortic valve disease)Failure of the lower left heart chamber (left ventricle)
Group 3: Pulmonary Hypertension From Lung Disease Different forms of lung disease can cause tightening in certain areas of your lungs, which is your body’s response to ensure that blood goes to areas of your lungs that are less affected by your lung disease. As a result, the overall blood pressure in your lungs goes up. This form of pulmonary hypertension may be caused by:
Chronic obstructive pulmonary disease (including emphysema)Pulmonary fibrosisSleep apnea and other sleep disordersLong-term living at high altitudes, in some people
Group 4: Pulmonary Hypertension From Chronic Blood Clots When a blood clot forms in your lungs and your body can’t dissolve it, the clot can cause scar tissue that blocks normal blood flow and makes the right side of your heart work harder. In this way, group 4 pulmonary hypertension is similar to PAH. But group 4 pulmonary hypertension is different because it’s caused by blood clots, and it may be treated or even cured by surgery to remove the clots. Not everyone, though, is a candidate for this surgery. Group 5: Pulmonary Hypertension From Other Disorders This category applies to pulmonary hypertension that seems to be connected to an underlying disease, but in a way that isn’t well understood. It may be caused by a long list of conditions, including:
Blood disordersOrgan disorders (such as sarcoidosis)Metabolic disordersTumors that press against pulmonary arteriesSplenectomy (spleen removal) (7,8)
Prognosis of PAH
Many different factors are likely to determine how much, and how quickly, your health gets better or worse once you’re diagnosed with PAH. If your PAH isn’t diagnosed until it has progressed to a severe stage — with frequent shortness of breath, fatigue, and inadequate oxygen in your blood — then you may only have a few years to live unless you get effective treatment. While treatment for PAH is often more effective at earlier stages of the disease, advances in therapies mean that even severe PAH may respond well to treatment. (1) While combinations of different drugs are usually considered the main treatment for PAH, your doctor may also recommend additional treatment options.
Medications for Pulmonary Arterial Hypertension
Your doctor may prescribe any number of drug combinations that are designed to directly treat your PAH. These medications may be taken by mouth as a pill, inhaled, or delivered intravenously (by IV). Drugs to directly treat PAH fall into the following categories:
ProstaglandinsEndothelin receptor antagonistsPhosphodiesterase type 5 inhibitorsIndividual drugs with different mechanisms
Your PAH may also be improved by taking “supportive therapies,” which don’t directly target your PAH but may reduce its negative effects. These drugs include:
Vasodilators (blood vessel widening drugs)Anticoagulants (anti-clot drugs)Diuretics (water pills, often taken to reduce swelling) (1,2)
Cardiopulmonary Rehabilitation Programs
Some people with PAH may benefit from a cardiopulmonary or pulmonary rehabilitation program, which consists of education and exercises to help you increase awareness of and strengthen your lungs and breathing. Cardiopulmonary rehabilitation classes typically take place in a group setting, which lets you meet other people with your condition to give and receive support. At the same time, you’ll learn exercises to help your breathing for use outside the class setting. This type of program is usually recommended for people with any type of lung disease, such as PAH, that causes frequent shortness of breath and interferes with daily activities even alongside other treatments. (1,9)
Supplemental Oxygen for Pulmonary Arterial Hypertension
Some people with PAH may need to take extra oxygen to improve their breathing. Depending on your symptoms, you may take supplemental oxygen at night, as you feel you need it, or all the time. This may mean carrying oxygen with you when you go out, especially if walking or other activity tends to make your breathing worse. (1,2)
Lung Transplantation for Pulmonary Arterial Hypertension
For certain severe cases of PAH, your doctor may recommend a lung transplant. This procedure tends to be effective at improving symptoms and restoring heart function, but comes with its own substantial risks — including infection and rejection of transplanted organs. If you undergo a lung transplant, you’ll need to take an anti-rejection medication for the rest of your life. Depending on the nature of your health problems, transplant options for PAH may include:
Heart-lung transplantSingle lung transplantDouble lung transplant (1,2)
CBD for Pulmonary Arterial Hypertension
In recent years, CBD — short for cannabidiol, a chemical component of cannabis (marijuana) — has been touted as a possible treatment for PAH. Unfortunately, any possible benefit in this area remains theoretical, since there haven’t been any rigorous scientific studies examining the effects of CBD in PAH. In an article on the potential effects of cannabis components on pulmonary hypertension and other forms of hypertension, published in February 2018 in the British Journal of Pharmacology, the researchers write that these chemicals may have numerous effects on the nervous system that could affect blood pressure in different areas of your body. These effects may depend on a person’s medical condition, age, and sex, and more research is needed to investigate how CBD might fit into a treatment strategy for PAH. (10) RELATED: A Single Drink a Day May Cause High Blood Pressure
Right-Side Heart Enlargement and Heart Failure
When your heart has to work harder to pump blood through narrowed arteries in your lungs, it can grow enlarged over time and eventually stop working effectively.
Blood Clots
Having increased blood pressure in your lungs makes it more likely that you’ll develop clots in the organ’s small arteries, which can be especially dangerous if you already have narrowed arteries.
Arrhythmia (Irregular Heartbeat)
When your heart has to work harder to pump blood through your lungs, you’re more likely to have an irregular heartbeat. This can potentially cause heart palpitations, dizziness, or fainting, which may be deadly in certain situations.
Bleeding
Increased blood pressure in your lungs increases the risk of blood vessel breakage and bleeding, which may cause you to cough up blood. Bleeding in your lungs can be a fatal complication. (8)
Potential Activity Restrictions and Limitations With Pulmonary Arterial Hypertension
Depending on how severe your PAH is, it may moderately to drastically restrict your daily activities and mobility. Any activity that strains your heart and lungs could potentially worsen your symptoms and even contribute to dangerous complications. Follow your doctor’s instructions about any forms of physical activity you should avoid. Generally, it’s a good idea to get some light exercise to maintain muscle strength and conditioning, so don’t restrict your activity more than is recommended. (1,2) New cases of PAH are diagnosed at a rate of only 1 to 2 people per million per year in both the United States and Europe, according to the National Organization for Rare Disorders. That translates to 500 to 1,000 new cases each year in the United States. (2) Women are three to five times more likely than men to develop PAH, with women between the ages of 30 and 60 at the highest risk. PAH doesn’t appear to be any more or less common in different racial or ethnic groups, with the possible exception of heritable PAH being less common in people of African ancestry. You’re more likely to develop a rare form of PAH if you live at a high altitude. If you have PAH or a family history of the condition, it’s advisable not to live at a high altitude. (2) RELATED: What Is Heart Failure? There are also forms of pulmonary hypertension (high blood pressure in the lungs) other than PAH that may lead to symptoms and treatment strategies that resemble those for PAH (see “Functional State of Pulmonary Arterial Hypertension”). Finally, there are health conditions that may result from PAH as complications (see “Complications of Pulmonary Arterial Hypertension”). Some lung and heart conditions may cause pulmonary hypertension in their advanced stages, and may also be associated with PAH. These conditions include:
Ischemic heart diseaseValvular diseaseCardiomyopathyInterstitial pneumonia (2)
Can Pulmonary Arterial Hypertension Be Prevented?
There are many different potential factors that contribute to the development of PAH. Some of these factors, such as the use of certain drugs, may be preventable. Others, such as your family history, can’t be prevented. And in many cases, the cause of PAH is unknown.
Can Pulmonary Hypertension Be Reversed?
A number of potentially effective treatments for PAH are available, including many different drug treatments. There may also be exercises you can do to reduce the negative effects of PAH. But there isn’t any known way to reverse PAH through lifestyle measures alone.
Is Pulmonary Hypertension the Same as Pulmonary Arterial Hypertension (PAH)?
Pulmonary hypertension is a broad category of conditions that includes five different subtypes. One of these subtypes is PAH.
How Do I Stay Up-to-Date With the Latest Treatments for Pulmonary Arterial Hypertension?
You can find helpful information about PAH treatments at the Pulmonary Hypertension Association.
Can Pulmonary Arterial Hypertension Be Misdiagnosed?
Almost any health condition can be misdiagnosed, but PAH can be particularly tricky to diagnose in the first place because its signs and symptoms are similar to those of other heart and lung conditions, as well as other forms of pulmonary hypertension. And if you have multiple health conditions, figuring out how they’re related can also be tricky, which may lead to an inaccurate diagnosis.
Can Pulmonary Arterial Hypertension Be Mistaken for Asthma?
While some symptoms of asthma and PAH may overlap, they have very different underlying causes, and PAH is generally considered much more severe. In some cases, it’s possible that a doctor may mistake PAH for a severe form of asthma, but doing the right diagnostic tests should clear up this mistake.
Can Pulmonary Arterial Hypertension Cause Erectile Dysfunction?
PAH and erectile dysfunction share many different potential underlying causes. While it’s impossible to account for all the factors behind erectile dysfunction — and some may be psychological — there isn’t any evidence that PAH directly causes erectile dysfunction.
Can Smoking Cause Pulmonary Arterial Hypertension?
Smoking can contribute to many different types of heart and lung disease, including certain forms of pulmonary hypertension. It isn’t clear, though, if smoking is directly linked to PAH, although some limited evidence suggests that it may be. (11)
Can You Fly With Pulmonary Arterial Hypertension?
Talk to your doctor about any activity or travel restrictions related to your PAH. All such recommendations are likely to be based on how effectively your condition is being treated, along with your overall health.
Does Pulmonary Arterial Hypertension Run in Families?
One form of PAH, known as heritable PAH, very clearly does run in families. Other forms of PAH may result from underlying health conditions that could possibly run in families, but the evidence for a family link is much weaker than for heritable PAH. American Lung Association: Pulmonary Arterial Hypertension (PAH) National Organization for Rare Disorders: Pulmonary Arterial Hypertension Pulmonary Hypertension Association
