What is pulmonary arterial hypertension, and is it a problem of my heart or lungs?

Hypertension means high blood pressure, and pulmonary arterial hypertension is a disorder in which the pressure in the pulmonary arteries (the blood vessels from the right side of the heart to the lungs) is abnormally high.

Pulmonary arterial hypertension (PAH) is a complex medical problem that is still relatively under-diagnosed and under-recognized today. Even though it was described by doctors nearly 100 years ago, our understanding of the problem has only really improved in the last few decades. We now have some concepts about who is at risk for PAH and what some of the causes or associated conditions are, what some of the mechanisms of PAH are at a cellular level, and how treatment for PAH might improve your symptoms.

PAH often causes symptoms that include shortness of breath, fatigue and chest discomfort, and can make it difficult to lead an active life, as activities of daily living, like walking, working, or even taking care of yourself and your family become harder. PAH often requires a series of medical tests to identify the most likely cause of the elevated pressures and how best to treat the problem.

All blood vessels are part of the circulatory or cardiovascular system (which includes the heart), but the pulmonary arteries are also considered part of the respiratory system (which includes the lungs).

In reality, the heart and the lungs are so closely interconnected that pulmonary arterial hypertension ends up affecting both how the lungs work and how the heart works. You may end up seeing both a heart or a lung doctor, or both, as part of the evaluation and treatment of pulmonary arterial hypertension.