What Is Pulmonary Hypertension?

Pulmonary hypertension (PH) is a chronic and progressive disease associated with high blood pressure in the blood vessels, known as the pulmonary arteries, that supply the lungs.

The right side of the heart pumps oxygen-poor blood into the pulmonary artery. The pulmonary artery branches into smaller blood vessels in the lungs to release carbon dioxide and pick up oxygen. Then, the oxygen-rich blood passes through the left side of the heart before being transported throughout the body.

Types of PH

The World Health Organization created five groups to classify types of PH, based on the underlying cause and symptoms of the disease.

Group 1, also called pulmonary arterial hypertension (PAH), is caused by a narrowing of the pulmonary arteries. There are multiple sub-types: idiopathic, meaning it has no known cause; inherited; due to drugs or toxins; and related to other conditions, such as HIV infection or congenital heart disease.

Group 2 includes PH caused by left heart disease. This is the most common type and includes pulmonary venous hypertension, which is when the heart is not able to efficiently carry blood away from the lungs.

Group 3 is PH due to lung diseases and/or hypoxia, which means low oxygen levels. Examples of such lung diseases include chronic obstructive pulmonary disease, known as COPD, pulmonary fibrosis, characterized by fibrosis or scarring of the lungs, and sleep apnea, which refers to repeated breathing stops and starts during sleep.

Group 4, caused by chronic blood clots in the lungs, is PH also known as chronic thromboembolic pulmonary hypertension (CTEPH), a rare form.

Group 5 refers to PH cases that do not fit into any of the other four groups and occur alongside other diseases. This can include blood disorders, metabolic disorders, sarcoidosis and other systemic disorders, tumors obstructing pulmonary arteries, or end-stage renal (kidney) disease.

Symptoms of PH

The main symptoms associated with pulmonary hypertension are shortness of breath, fatigue, dizziness or fainting, and chest pain. Swelling of the ankles, legs, and abdomen also is a common symptom as are blue-tinted lips and skin, and heart palpitations, or a racing heartbeat.

These symptoms can make it difficult to exercise, and even do such routine tasks as climbing stairs.

The increased blood pressure in the lungs means that the right side of the heart must work harder to pump blood through the arteries. This can lead to heart failure in later life.

Diagnosing PH

PH is very difficult to diagnose as its symptoms can be similar to those of other heart or lung conditions.

If the disease is suspected, physicians usually use several tests to confirm the diagnosis and to check for the condition’s severity. Among those tests is an electrocardiogram, a noninvasive assessment of electrical activity that enables the detection of abnormal heartbeats and strain on the lower right heart chamber (right ventricle).

An echocardiogram also can be used to examine the chambers of the heart, and its valves. This test allows physicians to evaluate heart enlargement, the pressure in the pulmonary arteries, and other issues such as congenital heart disease.

The gold standard for PH diagnosis is a right heart catheterization, a method that aims to measure the pressure in the pulmonary arteries and show the heart’s ability to pump blood. This procedure also is used to assess the efficacy of different treatments.

A procedure called lung ventilation or perfusion scan, which uses a tracer to show the air and blood flow in the lungs, also can be employed to evaluate whether blood clots are in the lungs’ vessels.

Patients also may undergo exercise tests, such as the six-minute walk test. As its name suggests, this test measures the distance a person can walk during six minutes. Another example is a cardiopulmonary test, a way to analyze the capacity of the lungs and heart to function as the patient exercises on a treadmill or bicycle.

Other assessments include blood tests, chest CT scans and MRIs, as well as lung function evaluations that include a noninvasive procedure called spirometry, which measures how much air a person can blow in or out of one’s lungs.


Last updated: July 6, 2021


Pulmonary Hypertension News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.