Causes and Risk Factors of Pulmonary Hypertension

Reviewed by: HU Medical Review Board | Last reviewed: February 2024

Pulmonary hypertension (PH) is a heart condition that interferes with the flow of blood through the heart and lungs. There are several causes and risk factors for PH. Before learning what causes this condition, it is helpful to understand what PH is and how it affects the body.1-3

What is pulmonary hypertension?

PH is characterized by high blood pressure in the pulmonary arteries. The pulmonary arteries carry blood from the heart to the lungs so the blood can receive oxygen. But in people with pulmonary hypertension, these arteries become narrow and constricted, making it difficult for blood to flow through them.1-3

How does pulmonary hypertension affect the heart and lungs?

PH mainly impacts the heart. As the pulmonary arteries narrow, the right side of the heart has to work harder to pump blood to the lungs. Over time, this extra strain can lead to right-sided heart failure.1-4

PH can also affect the lungs. The narrowing of pulmonary arteries limits the amount of blood that can flow through them, reducing the oxygen supply to the lungs. This can result in symptoms like shortness of breath, fatigue, and a dry cough.1-4

What causes pulmonary hypertension?

Often, the cause of PH is unknown. For some, PH is inherited. For others, it is often brought on by other medical conditions or environmental factors. Causes also may vary depending on the type of PH. Causes of PH can include:1-4

  • Genetics
  • Congenital heart defects (heat problems you are born with)
  • Left-sided heart failure
  • Heart valve diseases
  • Lung diseases
  • Other medical conditions


Some forms of PH – like pulmonary arterial hypertension – can be caused by an inherited gene passed down through a person's family.2-4

Congenital heart defects

Heart defects that are present when a person is born can impact the heart and its blood vessels. They can potentially lead to PH.2-4

Left-sided heart failure

Left-sided heart failure is when the left side of the heart weakens. This is the most common cause of PH in the United States.1-4

Heart valve diseases

Mitral valve and aortic valve disease are 2 heart valve diseases that can increase a person’s risk for PH.2-4

Lung diseases

For people with certain lung diseases, the risk of PH increases. These lung diseases include chronic obstructive pulmonary disease (COPD), interstitial lung disease, and sleep apnea.2-4

Other medical conditions

Other medical conditions can also increase a person’s risk of getting PH. These conditions include:2-4

  • Sickle cell disease
  • HIV
  • Glycogen storage diseases
  • Scleroderma
  • Liver disease
  • Lupus
  • Kidney disease
  • Thyroid disease

What are the risk factors of pulmonary hypertension?

Some risk factors can be avoided, while others cannot. Risk factors for PH may include:2-4

  • Family history of PH or blood clots
  • Older age
  • Chronic health conditions
  • Unhealthy lifestyle
  • Use of recreational drugs, such as methamphetamine
  • Environmental factors like exposure to asbestos and certain parasites

Can pulmonary hypertension be prevented?

There is no foolproof way to prevent PH. But certain lifestyle choices and habits can reduce the risk or severity of PH:3,4

  • Regular exercise – Getting regular physical activity helps maintain overall cardiovascular health. This reduces the risk of conditions that may lead to PH.
  • Healthy diet – Eating a heart-healthy diet rich in fruits, vegetables, lean proteins, and whole grains can help your cardiovascular system function at its best.
  • Avoiding tobacco – Smoking is a major risk factor for PH and other cardiovascular diseases. Quitting smoking can greatly reduce the likelihood of developing PH.
  • Treat high blood pressure – Be sure to take any blood pressure medicines as prescribed by your doctor.
  • Early detection and treatment – Getting regular checkups and prompt medical attention for any heart or breathing symptoms can lead to early detection of PH. These measures also can help prevent or manage potential causes of PH.

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