Pulmonary Hypertension

By Sophia Airhart, MD

Hypertension is a condition in which the blood flow in the arteries is persistently high. What we commonly know as HTN refers to the blood flow from the left side of the heart. (That's when you feel your pulse in your wrist). That's the high-pressure system within our body.

When you go into your doctor's office and they put the cuff on your arm, that's the blood pressure we're measuring.

Pulmonary hypertension is really blood flow into the lungs, which is much more difficult to measure. The blood flow that goes into the lungs comes from the right side of the heart, and that's a very low pressure system. Normally it's almost tenfold times lower than the blood flow going to the rest of your body.

Blood vessels in the lungs can become stiff, damaged or narrow, and the right side of the heart must work harder to pump blood through.

Pulmonary Hypertension Groups

Pulmonary hypertension (PH) is a general term used to describe high blood pressure in the lungs from any cause. There are five different groups of PH based on different causes. These groups are defined by the World Health Organization (WHO) and are referred to as PH WHO Groups.

Different types of pulmonary hypertension.

PH can be caused from other heart problems, like valve disease.

PH can be caused from lung disease or if you have blood clots.

Appropriate diagnosis is important to guide treatment. Clinic focus is deciding where the problem is, whether it's the blood vessels in the lungs, the heart (namely HFrEF, HFpEF or valvular disease), or an intrinsic lung disease, such as COPD or asthma. Then, deciding what the best therapy would be at that time.

WHO groups For groups 2 and 3, the treatment is targeted at the underlying heart and lung disease respectively. For WHO group 4 the treatment may be surgical.

In the case of WHO Group 1, pulmonary arterial hypertension (PAH), the arteries in the lungs become narrowed, thickened or stiff. This forces the right side of the heart to work harder to push blood through these narrowed arteries. The extra stress can cause the heart to lose its ability to pump enough blood through the lungs to meet the needs of the rest of the body. While PAH is one of the rarest of the WHO Groups, it primarily affects women and is diagnosed between the ages of 30 to 60. It can be treated with medications, but these are very costly. Besides the monetary cost, if a patient is misdiagnosed with PAH and instead has Group 2 PH for instance, the medications can cause the patient’s health to deteriorate.

Symptoms, Often Nonspecific

  • Dyspnea – When shortness of breath is greater than expected for a given level of exertion, it is considered a symptom of disease.
  • Fatigue, weakness
  • Palpitations
  • Chest pain
  • Syncope (fainting)
  • Abdominal distension – visible increase in the girth, width of the area between hips and chest.
  • Lower extremity edema (swelling)


  • History (family history of PH, taking diet pills, connective tissue disease
  • Physical exam
  • Chest x-ray
  • Electrocardiogram (ECG)
  • Echocardiogram – right heart disease, left heart disease, valve disease or congenital heart disease
  • Ventilation/perfusion nuclear medicine scan - Evaluate for evidence of chronic blood clots to your lungs
  • Right heart catheterization - gold standard test for diagnosis
  • Functional assessment



Learn more about heart failure on the Advanced Heart Disease webpage.

Sophia Airhart, MD, assistant professor of medicine, is a heart failure specialist with the Advanced Heart Failure, Mechanical Circulatory Support and Cardiac Transplantation Team at Banner – University Medical Center Tucson. She is board certified in internal medicine, cardiovascular disease, and echocardiography, and advanced heart failure and transplantation. She is a member of the American College of Cardiology's Heart Failure and Transplant Section, the Heart Rhythm Society, and the American Heart Association/American Stroke Association's Council on Clinical Cardiology.

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