Investigators plan to recruit 50 PAH patients from UofL PAH Clinic, with various degrees of severity (25 intermediate risk patients and 20 high risk patients) and 10 age and gender matched controls. PAH patients are evaluated at least every 6 months by the PAH Clinic and blood/urine samples will be obtained at each office visit. Blood, plasma and urine samples will be used to measure 31 metal levels including heavy metals (cadmium, arsenic, cobalt, lead etc.) and essential metals (calcium, copper, iron, zinc, potassium etc.) by the with ICP-MS via the service of ITEMFC. Interactions among the 31 metals in PAH patients, metal concentration differences between intermediate risk PAH, high risk PAH and control groups, the correlation between metal concentrations and the etiology, severity, duration, treatment, and progression of PAH/RV dysfunction over 12 months will be analyzed by CIEHS Biostatistics and Informatics Facility Core.