What is the Difference Between PH and PAH

The key difference between PH and PAH is that PH is a general term used to describe high blood pressure in the lungs due to any cause, while PAH is a chronic medical condition that causes the walls of the arteries of the lungs to tighten and stiffen, which eventually leads to high blood pressure.

Pulmonary hypertension (PH) is high blood pressure in the loop of vessels connecting the heart and lungs. This system carries fresh oxygenated blood from the lungs to the heart. While returning, this system carries used or oxygen-depleted blood back to the lungs. Pulmonary hypertension has several causes, such as pulmonary arterial hypertension (PAH), left heart disease, hypoxia, and other disorders such as hematologic disorders, systematic disorders, metabolic disorders, and tumoral obstruction. PH and PAH are two related terms used to describe high blood pressure.

CONTENTS

1. Overview and Key Difference
2. What is PH 
3. What is PAH
4. Similarities – PH and PAH
5. PH vs PAH in Tabular Form
6. Summary – PH vs PAH

What is PH (Pulmonary Hypertension) ?

Pulmonary hypertension (PH) is a general term used to describe high blood pressure in the lungs from any cause such as pulmonary arterial hypertension (PAH), left heart disease, hypoxia, other disorders such as hematologic disorders, systematic disorders (sarcoidosis), metabolic disorders, genetics, drugs and toxins, liver disease, HIV,  connective tissue disease (scleroderma), or tumoral obstruction. The World Health Organization first defined the classification of pulmonary hypertension in 1973, and this classification has been revised over the years.

The common symptoms of pulmonary hypertension are shortness of breath, chest pain, racing heartbeat, feeling lightheaded during physical activities, fainting, and swelling in the ankles. Moreover, this condition can be diagnosed through chest X-ray, CT-scan, MRI, lung function test, polysomnogram, lung ventilation/perfusion scan, blood test, electrocardiogram, and catheterization of the right heart. Furthermore, the treatment options for this medical condition may include medical therapies, clinical trials, lung transplantation, pulmonary thromboendarterectomy, and lifestyle modifications.

What is PAH (Pulmonary Arterial Hypertension)?

PAH (pulmonary arterial hypertension) is a chronic medical condition that causes the walls of the arteries of the lungs to tighten and stiffen, which eventually leads to high blood pressure. It is one of the main causes of pulmonary hypertension. This condition can be caused due to idiopathic, genetics (hereditary factors), or other diseases such as congestive heart failure, blood clots in the lungs, liver disease, illegal drug use, HIV, lupus, scleroderma, heart defect the patient is born with, lung diseases like emphysema, and sleep apnea.

The symptoms may include shortness of breath, fatigue, passing out, swelling in the ankles and legs, dizzy spells, weakness, fainting episodes, cough, cyanosis, enlarged liver and heart. The diagnosis can be made through medical history, echocardiogram, CT scan, ventilation-perfusion scan, electrocardiogram, chest X-ray, and exercise test. Furthermore, the standard treatments for PAH include medications such as prostaglandins, endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, other drugs like riociguat, selexipag, and supportive therapy (anticoagulants, diuretics, and oxygen).

What are the Similarities Between PH and PAH?

• PH and PAH are two related terms used to describe high blood pressure.
• PAH is one of the main causes of PH.
• Both may have a genetic predisposition.
• They may show similar symptoms.
• They are treatable through medications and supportive care.

What is the Difference Between PH and PAH?

PH (pulmonary hypertension) is a general term used to describe high blood pressure in the lungs due to any cause, while PAH (pulmonary arterial hypertension) is a chronic medical condition that causes the walls of the arteries of the lungs to tighten and stiffen, eventually leading to high blood pressure. Thus, this is the key difference between PH and PAH. Furthermore, PH can be caused due to pulmonary arterial hypertension (PAH), left heart disease, hypoxia, other disorders such as hematologic disorders, systematic disorders (sarcoidosis), metabolic disorders, genetics, drugs and toxins, liver disease, HIV, connective tissue disease (scleroderma) and tumoral obstruction. On the other hand, PAH can be caused due to idiopathic, genetics (hereditary factors), or other diseases such as congestive heart failure, blood clots in the lungs, liver disease, illegal drug use, HIV, lupus, scleroderma, heart defect a patient is born with, lung diseases like emphysema and sleep apnea.

The below infographic presents the differences between PH and PAH in tabular form for side by side comparison.

Summary – PH vs PAH

PH and PAH are two related terms used to describe high blood pressure. PH  is a general term used to describe high blood pressure in the lungs from any cause, while PAH  is a chronic medical condition that causes the walls of the arteries of the lungs to tighten and stiffen, which eventually leads to high blood pressure. So, this is the key difference between PH and PAH.

Reference:

1. “Types of PH.” Pulmonary Hypertension Association.
2. “Pulmonary Arterial Hypertension (PAH).” American Lung Association.

Image Courtesy:

1. “Pulmonary Hypertension” By BruceBlaus – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Pulmonary arterial changes suggestive of pulmonary hypertension in association with pulmonary veno-occlusive disease (PVOD) – Case 269 (8655563196)” By Yale Rosen from USA – Pulmonary arterial changes suggestive of pulmonary hypertension in association with pulmonary veno-occlusive disease (PVOD) – Case 269Uploaded by CFCF (CC BY-SA 2.0) via Commons Wikimedia