Definition of cause for English Language Learners. : 1  something or someone that produces an effect, result, or condition : something or someone that makes something happen or exist. : 2  a reason for doing or feeling something. : 3  something (such as an organization, belief, idea, or goal) that a group or people support or fight for.
Though PH patients have 68% probability of surviving after the first year of diagnosis, and the chances decrease to 34% four years later, according Ohio State University Lung Center, early diagnosis is critical in increasing the pulmonary hypertension life expectancy.
While the cause of primary pulmonary hypertension is uncertain, researchers think that in most people who develop the disease, the blood vessels are sensitive to certain factors that cause them to narrow.ulmonary hypertension is present when the blood pressure in the circulation of the lungs is measured at greater than 25 mm of mercury (Hg) at rest or 30 mm Hg during exercise. Pulmonary hypertension can be either primary or secondary: 1  Primary pulmonary hypertension. 2  The cause of pulmonary hypertension is unknown.