Not All Pulmonary Hypertension Is the Same. An Expert Explains Why It Matters.

Not all pulmonary hypertension is the same, and according to Panagis Galiatsatos, M.D., M.H.S., assistant professor at Johns Hopkins School of Medicine, community engagement co-director at Baltimore Breathe Center and author of “Medicine for the Greater Good: Achieving the Promise of Medicine Through Community Engagement,” understanding why that distinction matters could change everything about how patients approach their diagnosis and treatment.

Galiatsatos begins where most patients do: with blood pressure. Most people understand the familiar arm-cuff reading of around 120 over 80. What fewer people realize is that the lungs operate on a completely different, much lower-pressure system, sitting around 20 over 10. The right side of the heart, which pumps blood into the lungs, is designed to work against that low resistance. When pressure in the lung circulation rises, even modestly, that weaker right ventricle begins to struggle, and the consequences can be serious.

Pulmonary arterial hypertension (PAH) is classified into five groups, each defined by a different underlying cause. Group one, pulmonary arterial hypertension or PAH, is the most distinct. In PAH, the blood vessels themselves undergo a process called remodeling, physically narrowing in diameter in a way that is unique to the lungs and unrelated to the cholesterol-driven changes seen in the body’s other blood vessels. This group requires its own targeted treatments, including medications designed to dilate those vessels and interrupt the remodeling process.

Groups two through four arise from secondary causes: a backed-up heart in group two, destruction of lung tissue reducing the number of functional blood vessels in group three, and blood clots obstructing forward flow in group four. Galiatsatos uses a traffic jam analogy to explain the difference. In secondary pulmonary hypertension, the goal is to clear the accident causing the backup. In PAH, there is no single accident to clear. The road itself has narrowed, and that requires an entirely different set of interventions. Group five covers miscellaneous and poorly understood causes.

The psychological dimension of a PAH diagnosis, Galiatsatos notes, is particularly significant for group one patients, who tend to be younger and often arrive at diagnosis after months of being told they had asthma. Walking into a pulmonary hypertension clinic and encountering patients on oxygen or discussing transplant can be overwhelming for a young person who was living a full, active life just months earlier.

For those patients, Galiatsatos emphasizes that community matters as much as clinical care. Support groups, he says, provide something a physician visit alone cannot: shared lived experience, realistic trajectories told by people who have walked the same road, and the reassurance that comes from genuine camaraderie among those who truly understand.