Pulmonary arterial hypertension (PAH) is a disease that’s not very well known among the general population. If you or a loved one has been diagnosed with PAH, you likely have plenty of questions — for starters, is PAH a rare disease?

Yes, pulmonary arterial hypertension is rare. This lung disease is a form of pulmonary hypertension (PH), which damages the pulmonary arteries and causes high blood pressure in those blood vessels inside the lungs. In people with PAH, the heart’s right ventricle needs to work harder to pump blood into the arteries of the lungs. This type of PH raises the risk of right heart failure, blood clots, and other types of heart disease.

Although there’s currently no cure for PAH, timely and regular care from medical specialists (cardiologists, pulmonologists, rheumatologists, and more) can help slow disease progression and improve quality of life.

Below, we offer more details that answer the question “Is pulmonary arterial hypertension rare?” and discuss other less-known facts about the condition. Read on to learn more about this condition and get the care you need.

1. PAH Is a Very Rare Disease

PAH is a rare condition that affects about 15 to 55 people per million worldwide, per an article in The Lancet Respiratory Medicine. Approximately 500 to 1,000 new cases of PAH are diagnosed each year in the United States. About 15 percent to 20 percent of PAH cases are hereditary — known as heritable PAH — and linked to a family history of the disease.

About 30 percent of PAH cases are associated with connective tissue disease, which can damage blood vessels. PAH can also be linked to congenital heart disease.

Among the different forms of PAH are:

• Heritable PAH — Formerly known as familial or genetic PAH, this refers to PAH inherited from a relative with the condition.
• Associated PAH — Some people develop PAH when they have another medical condition, such as connective tissue disease, congenital heart disease, liver disease, or HIV.
• Idiopathic PAH — This is a type of PAH with an unknown cause (responsible for more than half of all cases)

Treatment approaches vary among the different types of PAH. Treatment for associated PAH involves also treating the underlying condition. For example, people with PAH linked to scleroderma (systemic sclerosis) don’t respond as well to treatments and are at risk of worse outcomes. Scleroderma is a type of connective tissue disease that can affect the vascular system and damage blood vessels.

2. An Accurate Diagnosis of PAH Can Take Several Years

PAH diagnoses are often delayed. According to the American Lung Association, PAH can be difficult to diagnose, and getting a proper diagnosis can take up to two years — or even longer. A study in the journal Respirology showed that one-third of people with PAH waited more than two years for a diagnosis, and another 25 percent had a delay of almost three years.

One myPHteam member wrote, “While I certainly feel discouraged with my newest diagnosis, I am relieved to have something that confirms all of my heart and lung symptoms.”

“I also struggled to get a diagnosis,” another member said. “So, go to a pulmonologist right away. By the way, you are not crazy — this is a rare and difficult disease to diagnose.”

The consequences of delayed diagnosis are serious. The Respirology study found that people with PAH who waited more than two years for an accurate diagnosis experienced worse outcomes compared with those who were diagnosed sooner. The authors noted that a delay of more than two years was associated with an 11 percent higher risk of death.

Symptoms of PAH, such as shortness of breath, chest pain, and fatigue, also appear in several other health conditions. Many doctors aren’t trained to recognize signs of PAH, which are key reasons diagnosis is often delayed.

3. Females Have a Higher Risk of Developing PAH Than Males

According to a study in Methodist DeBakey Cardiovascular Journal, females are almost twice as likely to develop PAH as males. That ratio lessens among older people, per the study: Females over age 65 are only 20 percent more likely than males to develop PAH.

Because younger women have a higher rate of PAH, researchers believe hormones may play a role in the development of PAH.

4. Race and Ethnicity May Play a Role in the Type of PAH a Person Develops

Although more research is needed on this topic, some studies have found differences in types of PAH across racial and ethnic groups. Understanding racial and ethnic differences in types of PAH can further help doctors in creating specialized PAH treatment plans.

The Pulmonary Hypertension Association reviewed several studies that found PAH types varied across racial and ethnic groups. The results showed the following among people with pulmonary arterial hypertension:

• African Americans were more likely to have connective tissue disease-associated PAH — that is, linked with scleroderma, rheumatoid arthritis, systemic lupus erythematosus, or mixed connective tissue disease.
• Hispanic people were more likely to have congenital heart disease-associated PAH.
• Non-Hispanic white people were more likely to have PAH associated with drug or toxin use. They were also more likely to have the heritable type.

5. Socioeconomic Status May Be a Factor in Rates of PAH

Socioeconomic status (SES) — a measure made up of factors like occupation, income, education level, and place of residence — may be a factor in outcomes from PAH. Lower socioeconomic status is linked to inadequate health insurance, delayed diagnosis, and a lack of follow-up care.

One systematic review led authors to recommend that SES be included as a variable in research on PAH. The study found that people with PAH and a lower income came to health care centers with more advanced disease. Diagnosing PAH before it becomes advanced is important for improving treatment outcomes.

Environmental risk factors related to low SES, such as high levels of air pollution, exposure to environmental toxins, and lower-quality diet, may also contribute to poorer outcomes from PAH. Researchers have recommended that health care professionals become better educated on the risks associated with lower SES in order to ensure offering appropriate care.

6. PAH Outcomes Have Improved Significantly in Recent Years

In recent decades, better management of PAH has significantly increased survival rates among people living with the disease. The one-year survival rate is now between 86 percent and 90 percent, up from 65 percent in the 1980s, according to the Journal of Investigative Medicine. Average long-term survival during that period increased from 2.8 years to 6 years.

A number of medications, such as prostacyclin drugs, can help reduce PAH symptoms. In some advanced cases of PAH, lung transplant may be advised.

Meanwhile, standards for diagnosis and disease management have also improved with tests such as:

• Right heart catheterization
• Echocardiogram
• Other types of lung and heart imaging (such as chest X-rays)
• Blood tests, which can evaluate blood flow in the heart and lungs and determine problems with the right side of your heart

Pulmonary function tests might also be done to see how well your lungs are working. These tests are commonly used to evaluate types of pulmonary hypertension and other lung diseases such as chronic obstructive pulmonary disease (COPD).

Risk-assessment tools help monitor disease progression and provide essential information that can guide PAH treatment plans. People with PAH should be evaluated every three to six months for their risk of mortality. Talk to your doctor to learn more about risk assessment for PAH.

Check In With Your Doctor

Your provider is your best guide on your journey with PAH. They can answer your questions about symptoms (such as shortness of breath or edema) and treatment side effects. Working together, you and your doctor can ensure that you have the best quality of life possible while living with PAH.

Talk to People Who Understand

On myPHteam, the social network for people with pulmonary hypertension and their loved ones, more than 53,000 members come together to ask questions, give advice, and share their stories with others who understand life with pulmonary hypertension.

Are you living with pulmonary arterial hypertension? What have you learned about the disease that has helped you better understand this rare condition? Share your thoughts and experience in the comments below, or share your story on your Activities page.