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What Is Pulmonary Hypertension?

Pulmonary hypertension can be understood as high blood pressure in the arteries in the lungs. It happens when the pressure in the blood vessels that run from the right side of the heart to the lungs gets too high.1

The right ventricle of the heart pumps blood to the lungs so that the blood can pick up oxygen and deliver it to the rest of the body. The pulmonary artery that carries blood from the heart to the lungs is very short, so its blood pressure is usually lower than the blood pressure in the arteries that carry blood from the heart to the rest of the body. With pulmonary hypertension, though, the pressure in the pulmonary artery is elevated.1,2

When comparing pulmonary hypertension to hypertension (more commonly known as high blood pressure), there's one big difference. Hypertension can elevate the pressure in arteries all over the body. Pulmonary hypertension only causes an increase in the arteries in the lungs.3

Causes and Risk Factors

What Causes Pulmonary Hypertension?

Pulmonary hypertension can have several causes, including:

  • Some heart diseases, including mitral valve disease, left heart disease, and congenital heart disease, may cause pulmonary hypertension.4

  • In a condition called chronic thromboembolic pulmonary hypertension (CTEPH), clots in the pulmonary arteries raise blood pressure in the lungs by blocking blood flow.5

  • Obesity is associated with the development of pulmonary hypertension.6

  • Obstructive sleep apnea is linked to pulmonary hyptertension.7 Living at a higher elevation can also play a role.8

  • Underlying conditions, also known as comorbidities, can contribute to the development of pulmonary hypertension.4,9 Examples of conditions that can raise pulmonary hypertension risk include:

    • Chronic liver disease, including cirrhosis10
    • Emphysema2
    • Chronic obstructive pulmonary disease (COPD)4
    • Tumors4
    • Pulmonary fibrosis11
    • Lupus3
    • Scleroderma3
  • This product has been taken off the market, but anyone who used it may have a higher risk of pulmonary hypertension.12

  • A genetic mutation is responsible for roughly 20% of pulmonary hypertension cases that don’t have other known causes. Most cases of pulmonary hypertension that have genetic underpinnings are tied to the bone morphogenetic protein receptor 2 (BMPR2) gene. This gene regulates the growth of cells in the walls of the small arteries in the lungs. When this gene malfunctions, the arteries narrow, restricting blood flow. Inheriting the genetic mutation doesn't necessarily mean a person will develop pulmonary hypertension.13

Pulmonary Hypertension Risk Factors
Pulmonary Hypertension Risk Factors and Prevention

Pulmonary hypertension can affect a person at any age. But the risk increases as one gets older, particularly after turning age 75.2 Here are other factors that can increase the risk:

  • Being born with XX chromosomes14
  • Obesity with obstructive sleep apnea14
  • Pregnancy14
  • High-altitude location14
  • Methamphetamine use14
  • Certain types of cancer therapies15
  • Infectious diseases, such as HIV and Hepatitis B or C16
  • Asbestos or silica exposure17,18
  • Smoking tobacco19


Pulmonary Hypertension Prevention

It isn't always possible to prevent pulmonary hypertension. However, there are steps that may reduce the likelihood of developing the condition. Strategies include:

  • Keeping high blood pressure under control2
  • Managing and monitoring coronary heart disease closely2
  • Managing or monitoring chronic liver disease, or chronic lung disease stemming from tobacco use2
  • Sticking to a diet that’s conducive to heart health4,20
  • Giving up smoking or tobacco use4,19

Types of Pulmonary Hypertension

Healthcare providers use the blanket term “pulmonary hypertension” to describe five types of the disease, each of which has its own cause and name.21

  • PAH happens when the arteries to the lungs become damaged without a clear reason. For example, these tiny conduits for blood may become narrower. The narrowing restricts blood flow and elevates blood pressure inside the lungs. This narrowing also taxes the heart, which must use more force to push blood through the arteries.22,23

    The right side of the heart must pump harder to overcome this higher pressure and push blood to the lungs. The added effort causes the heart to enlarge over time. The right side of the heart also stiffens, further reducing its pumping capacity. Eventually, the right side of the heart becomes so weak it can no longer adequately circulate blood—a condition called right-sided heart failure.3,22,23

    This type of PH has five types of causes. It can be idiopathic in nature, meaning the cause is unknown. PAH also can be genetically inherited, running in families. The use of drugs or illegal substances also may give rise to PAH. Problems with the heart at birth, known as congenital heart disease, can lead to PAH, and so can other conditions, including connective tissue disorders like lupus, scleroderma, and HIV.21

  • Group 2 PH stems from left-sided heart valve disease, which includes mitral valve or aortic valve disease.21,24,25 Mitral valve disease involves complications with the valve that separates the heart’s left chambers: the left atrium and left ventricle.24 Aortic valve disease involves problems with the valve situated between the heart’s lower-left chamber (the left ventricle) and the aorta (a major artery).21,25

  • This PH classification stems from issues with the lungs, including sleep apnea, pulmonary fibrosis (the accumulation of scar tissue between air sacs in the lungs),26 and chronic obstructive pulmonary disease (COPD).21

  • Blood clots in the lungs, known as pulmonary emboli, and other clotting disorders can lead to this PH classification.5,21

  • Group 5 of PH stems from a mix of other diseases and conditions. For example, blood disorders such as polycythemia vera (a type of blood cancer in which the body makes excess red blood cells) and essential thrombocythemia (a blood disorder involving excess production of platelets) can cause Group 5 PH.27,28,29 So can inflammatory disorders such as sarcoidosis, a disease in which pockets of inflammation arise in the body.27,30 Metabolic disorders, such as glycogen storage disease,27 a condition in which the body lacks an enzyme to properly store or use glycogen,31 can lead to Group 5 PH, and so can kidney disease, with some tumors causing clots or physical compression of the pulmonary artery from nearby tissues.27

Pulmonary Hypertension in Newborns

This condition threatens a baby's oxygen supply at birth.32 Approximately two out of every 1,000 infants born at full term have pulmonary hypertension.32 During pregnancy, the mother supplies the baby's oxygen, so the blood vessels in the baby's lungs are closed. After birth, those vessels should open with the first breath. With pulmonary hypertension in newborns, that doesn't happen as it should, and the blood vessels do not fully open. This can deprive the baby’s body (including the brain) of necessary oxygen and can cause heart and lung damage.32


Pediatric Pulmonary Hypertension
Pediatric Pulmonary Hypertension

Pulmonary hypertension in children may be inherited or it can develop from heart defects present at birth.33 It can also develop due to other conditions, such as cystic fibrosis or impaired heart muscle function.34

Affected children may experience:35

  • Decreased appetite
  • Vomiting or nausea when eating
  • Swelling in the legs, face, or arms
  • Inability to tolerate activity
  • Pain in the chest, dizziness, or shortness of breath
  • Pale or bluish appearance
  • Fainting
  • Younger children may be underweight
  • Older children may gain weight from inactivity or swelling


Portopulmonary Hypertension

This type of hypertension is linked to portal hypertension, a type of elevated pressure in the portal vein located in the liver.36,37 It can happen regardless of whether a person has existing liver disease.36

Pulmonary Hypertension Symptoms

Pulmonary Hypertension Symptoms

Symptoms of pulmonary hypertension may develop slowly over time. It may take months or years before symptoms are noticeable, as they worsen when the condition becomes more severe.38 Symptoms can include:

  • Fatigue4
  • Dizziness or fainting2,4
  • Shortness of breath from routine activity4
  • Chest pain2
  • Bluish color in the lips or skin4
  • Swelling in the legs, feet, or abdomen38
  • Fast or pounding heartbeat2
  • Hoarseness38
  • Nausea and vomiting38
  • Wheezing38

Of course, these symptoms can also occur in diseases other than pulmonary hypertension, which can make the diagnosis of pulmonary hypertension challenging.38 It's important to note that pulmonary hypertension symptoms are different from regular high blood pressure symptoms.38,39 In many cases, high blood pressure doesn't produce noticeable signs or symptoms.39 However, symptoms of high blood pressure can develop when pressures are very high (180/120) and may include:39,40,41

  • Nosebleeds
  • Bad headache
  • Chest pain
  • Breathing difficulties

Pulmonary Hypertension Complications

Having pulmonary hypertension may put one at risk for developing additional complications including, but not limited to:

  • Blood clots in the pulmonary arteries42
  • Liver damage due to higher pressure in the right side of the heart10,42
  • Pericardial effusion (fluid collection in the sac around the heart)42
  • Anemia (low red blood cell count or low hemoglobin in the blood)42,43
  • Irregular heartbeat42
  • Bundle branch blocks (delays in the electrical impulse that triggers the heartbeat)44
  • Bleeding within the lungs42
  • Pregnancy complications, including cardiac arrest, heart attack, respiratory failure, and stroke.45
  • Reduced life expectancy45

Diagnosing pulmonary hypertension can be difficult because it isn't immediately obvious during a regular check-up with a healthcare provider.46 Even when signs and symptoms emerge, they can be confused with other problems in the heart or lungs.46

If the doctor suspects that a patient might have pulmonary hypertension, they may recommend these tests to correctly diagnose the condition:46

This picture of the heart, chest, and lungs can reveal any heart or pulmonary artery enlargement.46

Blood tests can check kidney, thyroid, and liver function, as well as blood-oxygen levels.46

This test assesses how the heart’s electrical impulses are functioning. An electrocardiogram alone, however, cannot conclusively diagnose pulmonary hypertension. If a doctor suspects pulmonary hypertension, they will likely perform other tests.46

Echocardiograms use sound waves, delivered at a high frequency, to form images of the heart. These images help healthcare providers assess heart structure and function. For example, an echocardiogram can help identify issues with heart valves, study how well the heart is moving, or gauge the strength of heart beats.46,47

If any of the above tests point to pulmonary hypertension, this procedure can confirm it. A cardiologist will run a thin, flexible tube, called a catheter, through one of the patient’s blood vessels to the heart and pulmonary artery to measure the pressure.46

Pulmonary Hypertension Life Expectancy

Life expectancy differs between pulmonary hypertension groups. Age and gender may help predict a patient’s outlook. One study compared survival rates among groups of people with different types of pulmonary hypertension who did not receive transplants. Overall, average survival rates were about:48

  • 86% at 1 year
  • 67% at 3 years
  • 54% at 5 years


Pulmonary Hypertension Treatments

Except for CTEPH, which sometimes can be reversed by surgery, pulmonary hypertension often cannot be fully cured, but there are several treatments that can improve quality of life for people who have the condition.5 Research indicates that people who are diagnosed early tend to have better outcomes, making early detection and treatment important.49

Pulmonary Hypertension Medications

A number of approaches may be used to treat pulmonary hypertension, including medications and other types of treatments.49 Options include:

  • These medications help the blood vessels open to improve blood flow to the lungs.49 They can be injected, inhaled in a nebulizer treatment, taken by mouth, or delivered by infusion pump.49,50,51 There are several types of vasodilators used to treat pulmonary hypertension. Some of the side effects, depending on the type of vasodilator used, can include nausea, chest pain, and headache.52

    The first kind of medication used to treat pulmonary hypertension is a calcium channel blocker. Calcium channel blockers are only effective for some people. When effective, calcium channel blockers lower blood pressure.50,51

    Another type of medication used for pulmonary hypertension is guanylate cyclase stimulators. These medications relax the pulmonary arteries with nitric oxide, lowering the pressure in the lungs.51,53 They can cause an upset stomach and/or headache.54 Next, some patients may benefit from endothelin receptor antagonists. These medications counteract endothelin, a substance in the blood vessels that causes them to tighten.49,55 They can cause liver damage, so regular monitoring of liver function is recommended.55

    The final type of vasodilator used to treat pulmonary hypertension is phosphodiesterase 5 inhibitors. These medications may improve blood flow in the blood vessels in the lungs.49,56 Some of the side effects include headaches, stomach aches, and flushing.57

  • These medicines, called anticoagulants, can help treat blood clots that cause some cases of pulmonary hypertension.50 They can, however, increase the risk of bleeding.58

  • Also known as water pills, these drugs help the kidneys flush extra fluid out of the body.59 Doing so reduces the workload for the heart.60

  • Oxygen therapy may be administered if blood-oxygen levels drop too low.50 Patients will typically receive oxygen therapy by wearing a face mask or nasal cannula.50

Surgical Therapies for Pulmonary Hypertension

Some of the surgical therapies for pulmonary hypertension include:

  • This is the surgical removal of existing blood clots found in the pulmonary artery. In some cases, this surgery can help improve lung function.5,21

  • Experts sometimes recommend transplantation; this is usually limited to severe cases of pulmonary hypertension. Transplant recipients take immunosuppressant drugs to lessen the odds of their immune system rejecting new organs.61

Global Impact of Pulmonary Hypertension

Global Impact of Pulmonary Hypertension

Worldwide, between 50 million and 70 million people—nearly 1% of the world's population—have pulmonary hypertension, and that number is expected to grow as the global population ages.62 The lifetime cost associated with healthcare services to treat the condition is high. One study estimates that, in the U.S. alone, PAH creates an economic burden of anywhere from $98,000 to $117,000 per patient per year.63

Pulmonary hypertension is much more common in low- and middle-income countries, such as in Africa and the Middle East. In these locations, the incidence of HIV infection, congenital heart disease, and rheumatic fever, which increase the risk of developing pulmonary hypertension, are also higher.64

There are several challenges to treating patients with pulmonary hypertension in low- and middle-income countries. Diagnosis can take up to three years, and patients have limited access to healthcare services. Medications are scarce, and lung transplant is typically not an option.64

Frequently Asked Questions About Pulmonary Hypertension

  • With the exception of CTEPH, pulmonary hypertension cannot be cured, but existing treatments may improve quality of life for people who have the condition.5 Treatment options depend on the type of pulmonary hypertension, and sometimes address underlying causes, like heart or lung problems.21,50 For example, if thyroid disease or obstructive sleep apnea is responsible for pulmonary hypertension, addressing those problems can reverse the damage.65,66 In some cases, lifestyle changes, such as smoking cessation and a healthy diet, can help reduce the risk of pulmonary hypertension.2,50

  • Yes, pulmonary hypertension can be fatal. Researchers have said the disease is “characterized” by “diminished life expectancy.”45 Survival rates may vary depending on whether a person receives a transplant, as well as what type of pulmonary hypertension they have.4,48

    For example, one study found that the 5-year survival rate for people with incident and prevalent idiopathic pulmonary arterial hypertension who did not receive transplants was 67.1% and 58.9%, respectively. Compare that with the 5-year survival rate of incident and prevalent pulmonary arterial hypertension associated with known causes, which had 5-year survival rates of 56.8% and 39.2%, respectively. In the same study, the 1-year survival rate for these groups ranged from 90.6% to 79.2%.48

  • If the underlying condition that causes pulmonary hypertension is identified, then it is possible that the increased pressure may return toward normal with successful treatment.65,67

  • While it is possible to have both pulmonary hypertension and high blood pressure, pulmonary hypertension is not a cause of high blood pressure. One can have pulmonary hypertension without high blood pressure, and vice versa.2,3,50

  • There are several common underlying causes for pulmonary hypertension. Left-sided heart failure, liver disease, connective tissue disease, congenital heart disease, blood clots in the lungs, chronic lung disease, and genetics can all contribute to the development of the condition.21

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Area of Focus: Rare Disease

Pulmonary Hypertension is a focus of Pfizer’s Rare Disease Therapeutic Area. Visit the Rare Disease Page.

The information contained on this page is provided for your general information only. It is not intended as a substitute for seeking medical advice from a healthcare provider. Pfizer is not in the business of providing medical advice and does not engage in the practice of medicine. Pfizer under no circumstances recommends particular treatments for specific individuals and in all cases recommends consulting a physician or healthcare center before pursuing any course of treatment.