American Board of Internal Medicine (ABIM) Certification Practice Exam

What defines pulmonary hypertension (PH) in terms of resting mean pulmonary artery pressure?

1. 20 mm Hg or greater

2. 25 mm Hg or greater

3. 30 mm Hg or greater

4. 35 mm Hg or greater

The correct answer is: 25 mm Hg or greater

Pulmonary hypertension (PH) is defined by a resting mean pulmonary artery pressure (mPAP) of 25 mm Hg or greater. This definition is critical in both diagnosing and classifying the severity of pulmonary hypertension. The threshold of 25 mm Hg is based on extensive research and is widely accepted in clinical practice guidelines, including those established by the World Health Organization and the American College of Cardiology/American Heart Association. When the mean pulmonary artery pressure rises above this level, it indicates an increase in resistance within the pulmonary circulation, which can lead to a range of complications and necessitates a careful evaluation and management strategy tailored to the underlying cause of the hypertension. Recognizing this specific threshold helps clinicians differentiate normal pulmonary pressure from pathologically elevated levels that may warrant further investigation and potential intervention.