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Other Names for Pulmonary Hypertension

Group 1 pulmonary arterial hypertension (PAH) that occurs without a known cause often is called primary PAH or idiopathic (id-ee-o-PATH-ick) PAH.

Group 1 PAH that occurs with a known cause often is called associated PAH. For example, PAH that occurs in a person who has scleroderma might be called "PAH occurring in association with scleroderma," or simply "scleroderma-associated PAH."

Groups 2–5 pulmonary hypertension (PH) sometimes are called secondary PH.

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Pulmonary Hypertension Clinical Trials

Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Pulmonary Hypertension, visit

July 05, 2013 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.