Due to the difficulty of correctly diagnosing PAH patients and the complexity of the treatments available, it is highly recommended that PAH patients are referred to PH specialty centers. However, many specialty centers are not available to patients due to scarcity (only 156 centers exist across the nation) and geographical restrictions. For those patients who are able to reach a specialty center, a recent study found that they were being referred too late, were misdiagnosed, or were prescribed inappropriate medications. Because of the severity of PAH and the barriers that exist in referring patients to specialty centers, physicians who first encounter patients with suspected PAH, including cardiologists, pulmonologists, rheumatologists, and primary care physicians in the hospital setting, need to be aware of the most current WHO diagnostic strategies and treatment algorithms.