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.
Natural history of pulmonary hypertension in chronic obstructive pulmonary disease. Pulmonary hypertension in COPD progresses over time and its severity correlates with the degree of airflow obstruction and the impairment of pulmonary gas exchange 6, 7.