What is primary arterial hypertension?

Pulmonary arterial hypertension (PAH), formerly known as primary pulmonary hypertension, is a rare type of high blood pressure.

PAH affects the pulmonary arteries and capillaries. These blood vessels carry blood from the lower right chamber of your heart (right ventricle) into your lungs.

As the pressure in the pulmonary blood vessels builds up, the heart must work harder to pump blood to the lungs. Over time, this weakens the heart muscle. Eventually, it can lead to heart failure and death.

There’s no cure yet for PAH, but treatment options are available. Treatment may help relieve your symptoms, lower your chance of complications, and prolong your life.

Symptoms of pulmonary arterial hypertension

In the early stages of PAH, you might not have any noticeable symptoms. As the condition worsens, symptoms will become more noticeable. Common symptoms include:

  • difficulty breathing
  • fatigue
  • dizziness
  • fainting
  • chest pressure
  • chest pain
  • rapid pulse
  • heart palpitations
  • bluish tint to your lips or skin
  • swelling of your ankles or legs
  • swelling with fluid inside your abdomen, particularly in the later stages of PAH

You might find it hard to breathe during exercise or other types of physical activity. Eventually, breathing can become difficult during periods of rest, too.

Find out how to recognize symptoms of PAH.

Causes of pulmonary arterial hypertension

PAH develops when the pulmonary arteries and capillaries that carry blood from your heart to your lungs become constricted or destroyed.

Various conditions may trigger it, but the exact cause is unknown.

Around 20 percentTrusted Source of PAH cases are inherited. It involves genetic mutations that can occur in the BMPR2 gene or other genes.

The mutations can then be passed down through families, allowing the person with one of these mutations to have the potential to later develop PAH.

Other potential conditions that can be associated with developing PAH include:

  • chronic liver disease
  • congenital heart disease
  • certain connective tissue disorders
  • certain infections, such as HIV or schistosomiasis
  • sickle cell anemia
  • use of certain toxins or substances, including methamphetamine and banned or discontinued appetite suppressants

In some cases, PAH develops with no known related cause. This is known as idiopathic PAH. Discover how idiopathic PAH is diagnosed and treated.

Currently, there’s no known cure for PAH, but treatment can ease symptoms, reduce the risk of complications, and prolong life.


To help manage your PAH, your doctor might prescribe one or more of the following medications:

  • prostacyclin therapy to dilate (widen) your blood vessels
  • soluble guanylate cyclase stimulators to dilate your blood vessels
  • anticoagulants to prevent blood clots from forming
  • a class of drugs known as endothelin receptor antagonistsTrusted Source , such as ambrisentan (these drugs block the activity of endothelin, a substance that can narrow blood vessels)

If your PAH is related to another health condition, your doctor might prescribe other medications to help treat that condition. They might also adjust any medications that you currently take.

Find out more about the drugs that your doctor might prescribe.


Depending on how severe your PAH is, your doctor might recommend surgical treatment.

Options include atrial septostomy or a lung or heart transplant. Atrial septostomy can reduce the pressure on the right side of your heart. A lung or heart transplant can replace the damaged organ(s).

In atrial septostomy, your doctor will guide a catheter through one of your central veins to the upper right chamber of your heart. They’ll create an opening in the upper chamber septum. This is the strip of tissue between the right and left sides of the heart.

Next, your doctor will inflate a small balloon at the tip of the catheter to dilate the opening, causing blood to be able to flow between the upper chambers of your heart. This will relieve pressure on the right side of your heart.

If you have a serious case of PAH that’s related to severe lung disease, your doctor may recommend a lung transplant. Your surgeon will remove one or both of your lungs and replace them with lungs from an organ donor.

If you also have severe heart disease or heart failure, your doctor may recommend a heart transplant in addition to a lung transplant.

Lifestyle changes

Adjusting your diet, exercise routine, or other daily habits can help reduce your risk of PAH complications. These include:

  • eating a healthy diet
  • exercising regularly
  • maintaining a moderate weight
  • quitting smoking

Following your doctor’s recommended treatment plan may help relieve your symptoms, reduce your risk of complications, and prolong your life. Learn more about the treatment options for PAH.