Pulmonary hypertension (PH) is a serious condition characterized by a mean pulmonary artery pressure >=25mmHg on right heart catheterization (RHC). Despite advances in PH care, outcomes are still sub-optimal and further research is required into the pathobiology of the disease and development of biomarkers that can guide clinical care. The investigators are establishing a biobank to collect samples (blood, urine, stool) from patients with pulmonary hypertension, patients at high risk for pulmonary hypertension, healthy controls, and patients undergoing right heart catheterization. Specimens will be stored for future investigations.