If you or a loved one have been diagnosed with pulmonary hypertension or pulmonary arterial hypertension, you may have noticed the terms are sometimes used interchangeably — even by doctors or in trusted medical resources. This overlap can be confusing, especially since these medical conditions are related but not the same. Understanding the difference is an important first step in managing your health or supporting a loved one.

Just what is the difference between pulmonary hypertension and PAH? Let’s break it down. Pulmonary hypertension is a general term for high blood pressure in the arteries that connect the lungs and heart. (Specifically, “hypertension” means “high blood pressure” and “pulmonary” means “relating to the lungs.”) Pulmonary arterial hypertension is a specific type of PH caused by narrowing, damage, or blockages in the small arteries of the lungs. Think of it this way: All PAH is PH, but not all PH is PAH.

Both PH and PAH are serious health conditions. However, with early detection, appropriate management, and ongoing research into treatments, many individuals can see improvements in their symptoms and quality of life​.

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Prevalence

PH affects around 1 percent to 3 percent of the global population — about 80 million to 240 million people worldwide. In contrast, pulmonary arterial hypertension (PAH) is much rarer, with a prevalence of 15 to 30 cases per million people globally, or about 120,000 to 240,000 individuals worldwide. Both conditions are more common in females, according to AJMC. Certain types of heart failure related to PH and PAH also appear to be more prevalent in women than men, according to research cited in Frontiers in Aging.

Pulmonary hypertension (PH) affects around 1 percent to 3 percent of the global population. Pulmonary arterial hypertension (PAH) is much rarer.

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Causes

In pulmonary hypertension and pulmonary arterial hypertension, high blood pressure disrupts the normal flow of blood between the heart and lungs. This forces the right side of the heart to pump harder to overcome the increased pressure. Over time, this extra workload causes the right side of the heart to thicken, stiffen, and weaken, potentially leading to right heart failure.

PH can be caused by several other health issues, such as heart disease, blood clots in the lungs, and lung diseases like chronic obstructive pulmonary disease (COPD). In PAH, the pulmonary arterioles (small blood vessels in the lungs) get narrower over time. This makes it difficult for blood to flow smoothly through the lungs, leading to high pressure in the pulmonary blood vessels. When these vessels are stiff and narrow, blood has a hard time moving through the lungs. Even though blood eventually gets through, it struggles to spread out evenly, causing some areas of the lungs to not get enough blood to pick up oxygen effectively. As a result, the blood doesn’t gain enough oxygen while passing through the lungs.

Types of Pulmonary Hypertension

Different types of PH have different causes. The World Health Organization’s (WHO) international classification of diseases separates PH into five groups based on what causes them:

• Group 1 — Pulmonary arterial hypertension
• Group 2 — Pulmonary hypertension due to left heart disease
• Group 3 — PH due to lung disease
• Group 4 — PH due to blood clots in the lungs
• Group 5 — PH due to unknown causes or miscellaneous disease

Types of Pulmonary Arterial Hypertension

There are different types of PAH. Pulmonary arterial hypertension can be influenced by genetics or environmental factors. Some cases of PAH have no identifiable cause.

Associated PAH

PAH can develop as a result of other systemic health conditions. Almost half of PAH cases are associated with conditions such as:

• Liver disease
• HIV infection
• Congenital heart disorders
• Connective tissue diseases such as lupus and rheumatoid arthritis

Environmental PAH

Certain environmental exposures or substance use can contribute to the development of PAH. This can include the use of certain medications, such as methamphetamines or specific appetite suppressants.

Heritable PAH

Heritable PAH (HPAH), also called familial PAH, is linked to a specific gene mutation (changes) passed along the family tree. Scientists have found a genetic link to mutations on the BMPR2 gene in most people with heritable PAH. In fact, more than 350 BMPR2 gene mutations can cause HPAH. Between 15 percent and 20 percent of PAH cases are heritable.

Not all gene mutations are inherited. Some PAH-linked genetic mutations are spontaneous (occur at random on their own) or occur in people without a family history of PAH or PH.

Idiopathic PAH

Idiopathic pulmonary arterial hypertension is hypertension of the lungs that has no clear cause. About 40 percent of PAH cases have no identifiable cause.

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Symptoms

Symptoms of pulmonary hypertension, including PAH, can vary widely from person to person. Factors such as the stage of the condition, age, sex, and lifestyle can all influence how symptoms are experienced. In the early stages, some individuals may have no noticeable symptoms, while others may begin to experience subtle signs. As the condition progresses, symptoms typically become more severe.

Early-stage symptoms, which often appear during physical activity, may include:

• Dyspnea (shortness of breath) during exercise
• Fatigue or unusual levels of tiredness
• Angina (chest pain) or tightness
• Heart palpitations (a rapid or irregular heartbeat)

In more advanced stages, symptoms may occur even at rest and can include:

• Light-headedness or dizziness, especially during exertion
• Shortness of breath at rest
• Edema (swelling) in the ankles, legs, or abdomen (stomach area)
• Cyanosis (bluish lips or skin), caused by low oxygen levels in the blood
• Syncope (fainting), particularly during activity

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Diagnosis

Diagnosing pulmonary hypertension can be challenging. PH symptoms are common and resemble many other health conditions. Diagnosing PH often involves a process of elimination to identify the underlying cause and confirm the specific type of PH.

Accurately identifying the type of PH is crucial to treating and managing the condition. If you or your doctor suspect PH, diagnosis will likely start with a doctor giving you a thorough physical exam and capturing a detailed medical history.

Diagnosing pulmonary hypertension can be challenging. PH symptoms are common and resemble many other health conditions.

Diagnostic Tests

A doctor or health team may conduct a variety of tests to diagnose PH and PAH and determine the underlying cause. These may include:

• Blood tests to look for an increased risk of blood clots, stress on the heart, or anemia
• Cardiac MRI to get images of the heart's structure, functioning, and surrounding blood vessels
• Chest X-ray to capture images of the size and shape of the heart, pulmonary arteries, and other blood vessels
• Echocardiogram to estimate pulmonary artery pressures and evaluate heart function
• Electrocardiogram (ECG) to measure the heart’s electrical activity and detect strain or abnormalities in the right side of the heart
• Lung function tests to check for lung diseases, such as COPD or interstitial lung disease, that may contribute to PH
• Six-minute walk test to measure exercise tolerance and monitor changes in oxygen levels during physical activity

Confirming Pulmonary Arterial Hypertension

The gold standard for diagnosing PAH is right heart catheterization (RHC). This procedure directly measures the pressure inside the pulmonary arteries to confirm the diagnosis. The test provides critical data about pulmonary artery pressures, cardiac output, and blood oxygen levels. RHC is also used to monitor disease progression and assess response to treatment.

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Treatments

The treatment a person receives for any type of pulmonary hypertension will depend on the type of PH they have, the underlying cause, and their unique health characteristics. It is very important to have an accurate diagnosis of PH type to receive the best treatment. Some treatments for PAH may not have a beneficial effect on people with PH and could even harm people with certain kinds of PH.

Traditional treatments like diuretics and oxygen therapy are used to treat both PH and PAH. Depending on the severity or progression of a person's condition, a heart-lung transplant may also be an option.

Traditional treatments like diuretics and oxygen therapy may be used to treat both PH and PAH.

Treating Pulmonary Hypertension

Treatment for pulmonary hypertension focuses on managing symptoms, improving quality of life, and addressing the underlying cause of the condition. For example, people with group 2 PH (caused by left heart disease) are often treated with therapies targeting their heart condition. Those with group 3 PH (due to lung disease) may benefit from oxygen therapy or pulmonary rehabilitation to address breathing difficulties.

Among the five groups of PH, only group 4 PH — chronic thromboembolic pulmonary hypertension (CTEPH) — is potentially curable. Blood thinners (medications that prevent blood clots) can help manage CTEPH by preventing new clots from forming. Additionally, a surgery called pulmonary thromboendarterectomy (PTE) can remove blood clots from the pulmonary arteries. In cases where surgery isn’t an option, medications or a balloon pulmonary angioplasty may help manage symptoms​​. A balloon pulmonary angioplasty involves threading a catheter with a small balloon into the blocked pulmonary arteries and inflating the balloon to widen the vessels and improve blood flow.

Treating Pulmonary Arterial Hypertension

Treatments for PAH aim to manage symptoms, slow disease progression, and enhance quality of life. The U.S. Food and Drug Administration (FDA) has approved a variety of therapies, with newer options under development to expand treatment choices further. In addition to conventional treatments like calcium channel blockers and diuretics, there are oral, inhaled, intravenous (IV), and subcutaneous (under the skin) therapies designed to target the underlying mechanisms of PAH. In some cases, a doctor may recommend combination therapy — two or more therapies at once.

Pulmonary Hypertension vs. Pulmonary Arterial Hypertension: Prognosis

The prognosis for pulmonary hypertension and pulmonary arterial hypertension varies based on the specific type and underlying causes. Advances in treatment have significantly improved life expectancy for many individuals with PAH. For example, modern therapies have helped achieve a five-year survival rate of over 60 percent in some cases. This means half of people with PAH live at least five years after being diagnosed.

With ongoing advancements in diagnostics and therapies, many people with PH and PAH are living longer, healthier lives. Early and accurate diagnosis remains the cornerstone of effective management.

Connect With Others

On myPHteam, the social network for those who live with PH, more than 56,000 members come together to ask questions, give advice, and share their experiences of life with pulmonary hypertension.

What questions do you have about the differences between PH and PAH? What have your experiences been living with either condition? Share your thoughts in the comments below, start a conversation on your Activities page, or connect with like-minded members in Groups.